taxonID	type	description	language	source
03B387D3FFE4E510FF4AFBB6328AFA6F.taxon	description	The final dataset used for the Arcuphantes phylogeny comprised 27 ingroup terminals and 15 putative species. The resulting phylogenetic tree is illustrated in Fig. 27. Due to the low support values reconstructed for most of the nodes, probably related to the limited genetic data available in the analysis, it does not allow a thorough discussion of the phylogenetic relationship for most of the species. Nevertheless, each species included in the analysis forms a distinct monophyletic clade, with very long basal branches, supporting their morphological differences and taxonomic validity. The only exception seems represented by A. shiozakii and A. yakiyama, which are recovered as very closely related and part of the same clade. The newly described A. iseensis sp. nov. is confirmed as a genetically divergent lineage within the genus. It forms a well-supported, monophyletic clade, clearly separated from all other Arcuphantes species, including the closest A. shiozakii and A. yakiyama, thereby supporting its validity as a new species.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE4E510FF4AFD5E3340FBDF.taxon	description	The final dataset used for this phylogenetic analysis included 21 ingroup terminals representing six putative species, well-diagnosed by morphology. The resulting phylogenetic tree is shown in Fig. 26. Each Micrargus species is recovered as clearly separated clades, all supported by high node values. This includes M. cavernicolus, whose monophyly and close relationship with M. herbigradus (Blackwall, 1854) are strongly supported. Specimens of M. cavernicolus from both the type locality cave and the Mt. Fuji area merge in the same clade, confirming the morphological results and supporting them as belonging to the same species. Micrargus cf. herbigradus from China, retrieved from GenBank, is placed in the tree within the same clade as M. cavernicolus from Japan, suggesting conspecificity.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE4E511FF4AF8053765FD51.taxon	type_taxon	Type species: Nihonella chika Ballarin & Yamasaki, 2021 from Okayama Prefecture, Japan.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE4E511FF4AF8053765FD51.taxon	discussion	Remarks on genus Nihonella. Nihonella was recently established by Ballarin & Yamasaki (2021) as a monotypic genus based on a single troglophilic species, Nihonella chika. Until now, this genus was known only from caves in Okayama and Nara Prefectures in western Honshu, Japan (Japan Spider Catalog 2025). Here, we present new records based on newly collected specimens and others from the literature that were previously overlooked. Additionally, we describe a new Nihonella species found in caves in Kyushu and Shikoku islands. These new records extend the known distribution of the genus across western Japan (Fig. 28). Both known species of Nihonella show a preference for inhabiting the twilight zone of caves, dwelling not far from the cave entrance; however, different populations exhibit varying degrees of body depigmentation. For instance, in the new species described here, individuals from the cave in Ōita lack any pronounced morphological adaptations to the subterranean lifestyle, whereas individuals from the cave in Kōchi display a higher degree of depigmentation and overall lighter body coloration. It is plausible that Nihonella may exploit both caves and shallow subterranean environments, such as screes or similar, and even humid and shadowed epigean habitats. This assumption seems supported by the recent discovery of still undetermined Nihonella individuals, probably belonging to the same species here described, found among mossy stones near a spring in Ōita Prefecture (Y. Hino, in litteris).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE5E511FF4AFD5933F8FA2A.taxon	vernacular_names	(Japanese name: Hora-kosaragumo ホラコサラグモ)	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE5E511FF4AFD5933F8FA2A.taxon	materials_examined	New material examined. JAPAN: Okayama Pref., 6 ♀ Niimi City, Toyonaga Akouma, large and deep cave, 417 m, ~ 34.9864 ° N, 133.5844 ° E, 20. Apr. 2019, F. Ballarin & T. Yamasaki leg. (FBPC) ● ∙ 1 ♀, Maniwa City, Shimoazae, Suwa-do (諏ÜȒ), 195 m, 34.97030 ° N, 133.62425 ° E, humid cave with creek inside, 20. Apr. 2019, F. Ballarin & T. Yamasaki leg. (FBPC).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE5E511FF4AFD5933F8FA2A.taxon	diagnosis	Diagnosis and description. See Ballarin & Yamasaki (2021: 12, 13).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE5E511FF4AFD5933F8FA2A.taxon	discussion	Remarks. Nihonella chika is known for sparse records, in Okayama and Nara Prefectures, Honshu, all from the twilight and transition zones in caves (Ballarin & Yamasaki 2021, this work). Here we report new cave records. Additionally, we discovered that this species has already been illustrated in the literature, albeit as an undescribed species. Yaginuma (1963: 55, 59) reported a drawing of an unidentified linyphiid based on specimens collected from caves in the Akiyoshi plateau, Yamaguchi Prefecture. The localities mentioned in the text are as follows: Taisho-do cave (± 正Ȓ) (34.2767 ° N, 131.3203 ° E); Terayama-no-ana (ḢƜO 穴) (34.2450 ° E, 131.2516 ° E), and Kakekiyo-do (景清Ȓ) (34.2895 ° N, 131.3265 ° E). The author suggested that this species might belong to a new genus close to Tapinocyba Simon, 1884, but did not describe it. He also noted that the same species was found in other caves, without specifying the exact location. Based on Yaginuma’s drawings, the species can be identified as N. chika. These records extend the species’ distribution of approximately 200 km westward from the area reported in the original description, thus encompassing both the Kansai and Chugoku regions in western Japan (Fig. 28). Troglophilic species.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE5E51CFF4AF9C0338FF899.taxon	vernacular_names	(Japanese name: Tanikawa-hora-kosaragumo タニカワホラコサラグモ)	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE5E51CFF4AF9C0338FF899.taxon	description	Figs 1 A – I, 2 A – J	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE5E51CFF4AF9C0338FF899.taxon	materials_examined	Material examined. Holotype. ♂ JAPAN: Kyushu Is., Ōita Pref., Usuki City, Notsumachi Oaza Tomari, Hakusan Shrine (白Ɯ神社), nameless cave, 367 m, 33.0129 ° N, 131.7446 ° E, large cave with wide scree at entrance, 3. Aug. 2022, F. Ballarin & A. Tanikawa leg. (NSMT- 26846) Paratypes. 7 ♀, same locality and date as the holotype (3 ♀ NSMT- 26847, 2 ♀ MNHAH-B 6 - 000452, 2 ♀ MSNVR-Ar 052 - 053). Other material examined. JAPAN: Shikoku Is., Kōchi Pref., 1 ♂, 4 ♀, Kōchi City, Tosayamakuwao, Kuwao no Kaza-ana, 130 m, 33.6306 ° N, 133.5183 ° E, 12. Aug. 2025, T. Nagai & Y. Aoyagi leg. (TNPC- 20250812).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE5E51CFF4AF9C0338FF899.taxon	etymology	Etymology. The specific name is a patronym in honor of Mr. Akio Tanikawa, a renowned Japanese arachnologist who kindly assisted in collecting this and other cave-dwelling spider species during our field surveys in Japan.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE5E51CFF4AF9C0338FF899.taxon	diagnosis	Diagnosis. Species closely related to N. chika. Males of N. tanikawai sp. nov. can be easily separated from males of N. chika by having a wider and thicker distal suprategular apophysis (DSA), and embolus (vs both slimmer). Additionally, the secondary branch of the DSA (SDSA) is stocky and triangular (vs thread-like, slim and long) (cf. Fig. 1 F – I vs Ballarin & Yamasaki 2021: fig. 4 A – D). The palpal tibia apophysis is also proportionally shorter and more compact in the new species (vs. longer and slimmer), with a concave tip (vs. almost straight) bearing longer and thicker spines (vs short spines) (cf. Fig. 1 B, D, E vs Ballarin & Yamasaki 2021: figs 2 A, C; 3 A, D; 4 F). Females of N. tanikawai sp. nov. can be distinguished from females of N. chika by the shape of the ventral plate, straight posteriorly (vs margin extending out posteriorly), by the projections of the ventral plate kidney-shaped (vs oval) (cf. Fig. 2 A vs Ballarin & Yamasaki 2021: fig. 2 E), and by the posterior median plate wider and more squared (~ 1.5 times longer than wide), clearly visible when the epigyne is observed ventrally (vs narrower and more rectangular, ~ 2 times longer than wide; more oval, and not clearly visible when the epigyne is observed ventrally) (cf. Fig. 2 A – C vs Ballarin & Yamasaki 2021: fig. 2 E – G).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE5E51CFF4AF9C0338FF899.taxon	description	Description. Male (holotype). Habitus as in Fig. 2 E, F. Total length: 1.92, carapace 0.96 long, 0.75 wide. Carapace uniformly brown-reddish with faint darker rayed striae; chelicera and labium of same color, sternum dark brown. Cephalic area as in Fig. 2 G, distinctly elevated. AME black, other eyes silver. Eyes measurements: AME = 0.04; ALE = 0.07, PME = 0.07, PLE = 0.08. AME – ALE = 0.04, ALE – PLE = 0.00, PME – PLE = 0.07. Clypeus 0.18 long. Chelicera with five denticles on promargin and five – six small denticles on retromargin. Legs uniformly yellowish. Legs measurements: I 2.96 (0.82, 0.27, 0.70, 0.65, 0.52), II 2.76 (0.77, 0.27, 0.63, 0.61, 0.48), III 2.29 (0.65, 0.24, 0.50, 0.52, 0.38), IV 2.92 (0.80, 0.26, 0.75, 0.67, 0.44). TmI = 0.53, TmIV = absent, Leg tibial spine formula = 1 - 1 - 1 - 1. Opisthosoma dark gray with faint light marks and narrow transversal stripes on dorsal side, ventral side of same color with two parallel rows of lighter dots at sides; spinnerets yellow. Palp as in Fig. 1 A – C. Embolic division as in Fig. 1 F – I. Tibia elongated, bearing one trichobothrium. Tibial apophysis as in Fig. 1 D, E, elongated, approx. as long as cymbium, partially covering it. Tip of tibial apophysis with concave border, divided into two prongs covered with short, thick spines, proximal prong with a thick tuff of thin, curved macrosetae (Fig. 1 E). Paracymbium stumpy, relatively short, lacking any apophyses. Tailpiece of radix (TP) protruding posterior-prolaterally, ending with long, thin, hook-like radical apophysis (RA) curved frontally. Distal suprategular apophysis (DSA) well-developed, thick, curved ventro-prolaterally, ending with rounded tip. Secondary branch of distal suprategular apophysis (SDSA) hypertrophic, triangular, thick and stumpy, strongly protruding ventrally, ending with a sharp tip. Median membrane (MM) transparent and barely visible, protruding retrolaterally. Embolus (E) wide and flat, hook-like, curved ventro-posteriorly, ending with a sharp tip. Female (one of the paratypes). Habitus as in Fig. 2 H, I. Total length: 2.29, carapace 1.10 long, 0.84 wide. Cephalic area as in Fig. 2 J, not elevated. Eyes measurements: AME = 0.04, ALE = 0.08, PME = 0.08, PLE = 0.09, AME – ALE = 0.03, ALE – PLE = 0.00, PME – PLE = 0.05. Clypeus 0.17 long. Leg measurements as follows: I 3.29 (0.92, 0.30, 0.82, 0.70, 0.55), II 2.99 (0.85, 0.30, 0.72, 0.63, 0.49), III 2.6 (0.77, 0.26, 0.58, 0.59, 0.40), IV 3.21 (0.87, 0.28, 0.85, 0.73, 0.48). Other somatic characters as in male. Epigyne and vulva as in Fig. 2 A−D. Ventral plate (VP) of epigyne with flat border posteriorly. Posterior median plate (PMP) wider than long, clearly visible among lateral walls in ventral view (Fig. 2 A), protruding posteriorly, approximately trapezoidal in posterior view (Fig. 2 C). End of copulatory grooves with kidney-like inflation, forming two thick projections extending ventrally (PV, Fig. 2 A−C). Copulatory openings (CO) located under PV, approximately at their apex. Copulatory grooves (CG) reaching posterior side of spermatheca with a twisted course. Spermatheca (S) small, round. Size variation. Female (n = 5): total length: 2.11 – 2.31, carapace length: 1.00 – 1.09, width: 0.80 – 0.84.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE5E51CFF4AF9C0338FF899.taxon	distribution	Distribution and ecology. Nihonella tanikawai sp. nov. is currently known only from the type locality cave in eastern Kyushu and a single cave in Shikoku islands, approximately 180 km apart (Fig. 28). The new species was found in the twilight zone of the caves, in areas covered by scree, building simple sheet webs in empty spaces among the rocks. Troglophilic species.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE9E51DFF4AFF183728FBC5.taxon	type_taxon	Type species: Neriene herbigradus Blackwall, 1854 from United Kingdom.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE9E51DFF4AFF183728FBC5.taxon	discussion	Remarks on genus Micrargus in Japan. Micrargus currently includes 17 valid species, most of which are distributed in the Palaearctic or Nearctic realms, with only one species, M. fuscipalpis (Denis, 1962), recorded in East Africa (World Spider Catalog 2026). To date, Japan hosts five species, three of which are known only from their type localities and have never been recorded after the original descriptions: M. cavernicolus Wunderlich, 1995, known only from a few specimens from Sekiya-dokutsu cave in Iwate Prefecture and a single, unconfirmed record from Tochigi Pref.; M. hokkaidoensis Wunderlich, 1995, known only from a single male from Mt. Daisetsu in Hokkaido (the female remains unknown), and M. nibeoventris (Kishida, 1942), known only from a few specimens from Saisho-do cave in Nagano Prefecture (World Spider Catalog 2026; Japan Spider Catalog 2025). The other two species show a wider distribution: M. herbigradus (Blackwall, 1854), ranging from Europe and North Africa to Japan, and M. apertus (O. Pickard-Cambridge, 1871) with a disjunct distribution in Europe and Japan. In Japan, both species are known from scattered epigean records in central-east Honshu and Hokkaido (Japan Spider Catalog 2025). Micrargus species are usually difficult to identify due to general similarities in the shape of the male palp and epigyne / vulva, which have been a frequent cause of misidentification among closely related species. One of the most reliable diagnostic characters for species identification in this genus, the shape of the embolic tooth in the male palp (Rėlys & Weiss 1997), has often been overlooked in the Japanese species, which have never been properly compared with one another or their European counterparts. This, together with the lack of modern molecular analysis, highlights the need for a thorough revision of the Japanese species. Here we illustrate in detail both the male and female of M. cavernicolus based on the newly collected specimens from the type locality and other caves in the Mt. Fuji area, and we morphologically compare the species with the closely related M. herbigradus from Europe. Additionally, our molecular analysis further supports the validity of the species and suggests close relationships, and probably conspecificity, with individuals from China (Fig. 26).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE9E51AFF4AFBEC337EF8A5.taxon	vernacular_names	(Japanese name: Hora-gomagumo ホラゴマグモ)	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE9E51AFF4AFBEC337EF8A5.taxon	description	Figs 3 A – F, 4 A – H	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE9E51AFF4AFBEC337EF8A5.taxon	materials_examined	Material examined. JAPAN: Iwate Pref., 2 ♂, 2 ♀ (topotypes), Ōfunato City, Sekiya Hikoroichi, Sekiya-dokutsu cave (関谷Ȓ窟), 39.1275 ° N, 141.6724 ° E, 14. Dec. 2019, S. Watanabe leg. (1 ♂, 1 ♀ NSMT, 1 ♂, 1 ♀ FBPC) ● Shizuoka Pref., 2 ♂, 11 ♀, Fujinomiya City, Hitoana, Shin-ana Cave (Ế 穴), long and humid lava cave, 725 m, 35.3641 ° N, 138.5947 ° E, 3. Dec. 2022, F. Ballarin & T. Nagai leg. (1 ♂, 6 ♀ MNHAH, 1 ♂, 5 ♀ FBPC) ● Kumamoto Pref., 1 ♂, Itsuki vil., Uchitani, Uchitani-do cave (H 谷Ȓ), 32.2605 ° N, 130.4402 ° E, 3. Sep. 2024, Y. Aoyagi leg. (TNPC). Other material examined. Micrargus apertus: ITALY: Lombardia Region, 2 ♂, 1 ♀, Bergamo, Averara, Alpe Cul, southern slope, 1900 m, pitfall trap, 29. Oct. 2022 – 23. May. 2023, O. Lodovici & P. Pantini leg. (MSNB) ● M. herbigradus: ITALY: Lombardia Region, 1 ♂, 1 ♀, Lucca, Esino Lario, Ortanella, thermophilous forest, 1100 m., pitfall trap, 6. Jul – 11. Aug. 1999, P. Pantini leg. (MSNB).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE9E51AFF4AFBEC337EF8A5.taxon	diagnosis	Diagnosis. Species closely related to M. herbigradus (see Fig. 26) from which males can be recognized by the different shape of the embolic tooth, longer and completely embedded in the related membrane, and by the shorter but wider membrane (vs shorter embolic tooth, protruding anteriorly from the membrane, membrane thinner and longer in the latter species (cf. Fig. 4 B vs Fig. 4 A). Females of the two species are very similar and difficult to separate. See also Wunderlich (1995: 532) for the diagnosis with the other Japanese species.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE9E51AFF4AFBEC337EF8A5.taxon	description	Redescription. Male. Habitus as in Fig. 4 G. Total length: 1.84, carapace 0.94 long, 0.78 wide. Carapace dark brick red with faint darker rayed striae; chelicera, labium, and sternum of same color. Cephalic area distinctly elevated. AME black, other eyes silver. Eyes measurements: AME = 0.04; ALE = 0.06, PME = 0.05, PLE = 0.06. AME – ALE = 0.04, ALE – PLE = 0.00, PME – PLE = 0.06. Clypeus 0.16 long. Chelicera with three denticles on promargin and four – five on retromargin, the basal ones the largest. Legs uniformly yellowish. Legs measurements: I 2.80 (0.80, 0.22, 0.73, 0.56, 0.49), II 2.53 (0.75, 0.22, 0.61, 0.51, 0.44), III 2.06 (0.60, 0.20, 0.44, 0.44, 0.38), IV 2.65 (0.79, 0.21, 0.71, 0.52, 0.42). TmI = 0.32, TmIV = absent, Leg tibial spine formula = 2 - 2 - 1 - 1. Dorsal opisthosoma and spinnerets uniformly light gray-yellowish, ventral side slightly darker. Palp as in Fig. 3 A – C. Tibia ~ 1.5 x length of patella, bearing two trichobothria. Tibial apophysis as in Fig. 4 C, lobated, elongated anteriorly. Cymbium ovoid. Paracymbium hook-like, strongly curved. Bulb as in Fig. 3 DF. Median membrane (MM) transparent and lobated, protruding antero-dorsally. Embolus (E) long and filiform, convoluted; embolic tooth (ET) as in Fig. 4 B, thorn-like, straight, completely embedded in the related membrane. Female. Habitus as in Fig. 4 H. Total length: 1.77, carapace 0.84 long, 0.71 wide. Eyes measurements: AME = 0.04, ALE = 0.06, PME = 0.05, PLE = 0.06, AME – ALE = 0.04, ALE – PLE = 0.00, PME – PLE = 0.05. Clypeus 0.15 long. Chelicera with five large denticles on promargin, three small denticles on retromargin. Leg measurements as follows: I 2.71 (0.80, 0.23, 0.70, 0.53, 0.45), II 2.45 (0.75, 0.24, 0.56, 0.47, 0.43), III 2.01 (0.59, 0.22, 0.43, 0.42, 0.35), IV 2.64 (0.79, 0.22, 0.70, 0.51, 0.42). Opisthosoma uniformly light yellow. Other somatic characters as in male. Epigyne and vulva as in Fig. 4 D – F. Epigynal base (EB) wide. Copulatory openings (CO) located at the base of pockets. Copulatory grooves (CG) long, strongly convoluted, reaching interior side of spermatheca with a long and twisted course. Spermatheca (S) round. Size variation. Male (n = 4): total length: 1.75 – 1.85, carapace length: 0.92 – 0.94, width: 0.74 – 0.78. Female (n = 5): total length: 1.72 – 1.88, carapace length: 0.83 – 0.96, width: 0.70 – 0.72.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE9E51AFF4AFBEC337EF8A5.taxon	distribution	Distribution and ecology. Micrargus cavernicolus seems distributed across the whole mainland Japan, from eastern Honshu to Kyushu (Fig. 28), and possibly widespread outside Japan. All currently confirmed records refer to caves where this species builds small sheet webs in the crevices and empty spaces among rocks on the floor near the entrance, and in the twilight and transition zones. Troglophilic species.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFE9E51AFF4AFBEC337EF8A5.taxon	discussion	Remarks on classification and misidentification of M. cavernicolus. This species was originally described by Wunderlich (1995), based on specimens collected in Sekiya-dokutsu Cave in Iwate Prefecture. Since its original description, no further records have been reported except for an epigean record from Mt. Komaru in Tochigi Prefecture based on a single female (Suganami 2018). Due to the notorious difficulty in recognizing female individuals of Micrargus species, this record remains unconfirmed. However, our survey confirms the presence of this species in other caves across mainland Japan, suggesting that its distribution is much wider than previously expected and may also extend to epigean habitats. Our morphological and molecular analyses identified clear differences between M. cavernicolus and M. herbigradus, particularly in the shape of the embolic tooth, confirming that M. cavernicolus is a distinct species. Additionally, a sequence of a Micrargus individual from China, harvested from GenBank and identified as M. cf. herbigradus, shows a close relationship and a low genetic distance (0.7 %) with the Japanese M. cavernicolus (see Fig. 26, Table 2). This suggests possible conspecificity and a potential wider distribution of the species extending to mainland China. Although we did not have the opportunity to examine any Japanese individuals attributed to M. herbigradus, the inferred extensive distribution of M. cavernicolus suggests that epigean records of M. herbigradus from Japan, and possibly from East Asia, may represent misidentifications of this species. Further studies involving Chinese specimens identified as M. herbigradus may shed new light on this taxon. Wunderlich (1995), in his description of M. cavernicolus, did not directly compare this species with M. nibeoventris, likely due to the presumed loss of the type material (Wunderlich, 1995: 531). He relied solely on the original drawings, which do not show important diagnostic characters necessary for accurate identification (e. g., the embolic tooth). Similarly, we were unable to obtain any new individuals of M. nibeoventris for comparison as access to Saisho-do, the type locality cave located in Nagano Prefecture, is currently restricted. Given the newly discovered wide distribution of M. cavernicolus and the challenges in identifying Micrargus species based on general images of external palps, it is plausible that M. cavernicolus may represents a junior synonym of M. nibeoventris. This hypothesis should be tested once freshly collected samples of M. nibeoventris from Saisho-do cave become available.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFEDE519FF4AFF50317DFE79.taxon	type_taxon	Type species: Linyphia angulipalpis Westring, 1851 from Sweden.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFEDE519FF4AFF50317DFE79.taxon	discussion	Remarks on genus Anguliphantes. This genus currently includes 17 species with a predominantly Palaearctic distribution, spanning from Europe to East Asia, with two species recorded from India (World Spider Catalog 2026). Here, we report this genus from Japan for the first time.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFEDE506FF4AFE7033F8F8E9.taxon	vernacular_names	(Japanese name: Hanadaka-kadosaragumo ハナダカカドサラグモ)	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFEDE506FF4AFE7033F8F8E9.taxon	description	Figs 5 A – E, 6 A – F	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFEDE506FF4AFE7033F8F8E9.taxon	materials_examined	Material examined. JAPAN: Yamagata Pref., 1 ♂, Yonezawa City, Kariyasu Banseicho, collapsed abandoned railway tunnel with numerous fallen rocks on the floor (栗ŦNJdz), 37.8661 ° N, 140.2633 ° E, 17. Oct. 2019, F. Ballarin & K. Endo leg. (MNHAH-B 6 - 000456).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFEDE506FF4AFE7033F8F8E9.taxon	diagnosis	Diagnosis and description. See Paik (1965: 26, 27; 1985: 1 – 3). Male total length: 0.94, carapace 0.51 long, 0.46 wide. Male habitus as in Fig. 6 E, F; male palp as in Figs. 5 A – E; 6 A – D.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFEDE506FF4AFE7033F8F8E9.taxon	distribution	Distribution and ecology. Anguliphantes nasus is recorded in the Russian Far East, Northeastern China, Korea, and now Japan (World Spider Catalog 2026). We collected a single male under rocks on the floor in the twilight area of an abandoned railway tunnel (Fig. 28). Other records in the literature outside Japan refer to epigean habitats. Troglophilic species.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF2E507FF4AF8003734FB75.taxon	type_taxon	Type species: Arcuphantes fragilis Chamberlin & Ivie, 1943 from United States.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF2E507FF4AF8003734FB75.taxon	discussion	Remarks on genus Arcuphantes in Japan. Arcuphantes is a relatively broad genus comprising 61 species with a distribution spanning from East Asia (Japan: 28 species; Korea: 19 species; China: one species; Mongolia: one species) to North America (U. S. A.: 12 species, Canada: one species). One third of the described species (20 species) are currently known based on a single sex, 16 from females only and four from males only (World Spider Catalog 2026). An additional 10 species, all from Japan, are currently classified as Fusciphantes Oi, 1960, which several authors consider as a junior synonym of Arcuphantes (see Tanasevich 2010; Nakano et al. 2017; and World Spider Catalog 2026). However, this synonymization has never been officially formalized, and thus, in this work, we refer to Arcuphantes sensu stricto only. With 28 known species (and possibly 10 more currently named as Fusciphantes), Japan is the country that boasts the highest number of Arcuphantes species worldwide, most of which show a limited geographic distribution within the country, often confined to a few close localities (Japan Spider Catalog 2026). Nevertheless, the true magnitude of the genus' diversity in Japan is likely still underestimated, with new species recently described (Ono et al. 2024, Suzuki 2025) and several other yet to be discovered (Nakano et al. 2017). Arcuphantes are typically found in humid and shaded environments such as narrow valleys, thick forest leaf litter, screes, and other similar habitats where they spin their webs among crevices and empty spaces among rocks, logs, and leaf litter. Caves or cave-like environments are also preferred habitats for Arcuphantes species, often inhabiting the cave entrance or the twilight zone. Currently in Japan 12 Arcuphantes species are known to exploit subterranean habitats: A. ashifuensis Oi, 1960; A. digitatus Saito, 1992; A. fujiensis Yaginuma, 1972; A. elephantis Ono and Saito, 2001; A. hikosanensis Saito, 1992; A. iriei Saito, 1992; A. longissimus Saito, 1992; A. rostratus Ono & Saito, 2001; A. saragaminensis Ono & Saito, 2001; A. tamaensis Oi, 1960; A. troglodytarum Oi, 1960; and A. uenoi Saito, 1992 (Ballarin et al., unpublished). Most of the species are likely troglophilic as they are found in both epigean and hypogean habitats, do not exhibit special morphological adaptations to the cave life, and maintain well-developed functional eyes, pigmentations, and a clear dorsal pattern. The only exception seems to be A. troglodytarum, endemic to two caves in Shiga Prefecture, which seems to have a deeper bond with the subterranean environment, also exhibiting some degrees of depigmentation and eye reduction (Yaginuma 1976). Here, we report new cave records of Arcuphantes species previously recorded only in epigean habitats, we describe the previously unknown males of A. ashifuensis and A. longissimus, and we redescribe the poorly known A. tamaensis and A. troglodytarum, whose original descriptions of the males were overlooked by Oi (1960). Additionally, we describe a new Arcuphantes species, A. iseensis sp. nov., from Mie Prefecture, found primarily in caves, thereby increasing our understanding of the taxonomy and habitat preferences of this genus in Japan.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF3E502FF4AFB7D376DF985.taxon	vernacular_names	(Japanese name: Ashuu-yamisaragumo アシュウヤミサラグモ)	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF3E502FF4AFB7D376DF985.taxon	description	Figs 7 A – H, 8 A – H	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF3E502FF4AFB7D376DF985.taxon	materials_examined	Material examined. JAPAN: Fukui Pref., 7 ♂, 5 ♀, Obama City, Shimonegori, Shiraishi-no-ana cave (白ƂO穴), 35.4421 ° N, 135.7902 ° E, 3. Oct. 2019, F. Ballarin & A. Tanikawa leg. (4 ♂, 2 ♀, NSMT, 3 ♂, 3 ♀, FBPC).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF3E502FF4AFB7D376DF985.taxon	diagnosis	Diagnosis. Males of A. ashifuensis can be easily distinguished from males of any other Japanese Arcuphantes species by the unique shape of the posterior part of the terminal apophysis of radix bearing a massive, ribbon-like projection (PTA 2) folded along the longitudinal line forming a groove. Females are easily distinguished by the general shape of the epigyne ending with a unique arrow-like tip (cf. Figs 7 A, B, F – H, 8 A, B vs Ono et al. 2009: figs. 726 – 797).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF3E502FF4AFB7D376DF985.taxon	description	Description. Male. Habitus as in Fig. 8 F. Total length: 3.23, carapace 1.60 long, 1.35 wide. Carapace nearly oval, uniformly reddish brown with darker radial bands. Chelicera and maxillae of same color. Labium and sternum black brown. Cephalic area as in Fig. 8 E. Eyes well developed, silver with black basal area. Eyes measurements: AME = 0.08; ALE = 0.11, PME = 0.12, PLE = 0.11, AME – ALE = 0.13, ALE – PLE = 0.01, PME – PLE = 0.08. Clypeus 0.28 long. Chelicera as in Fig. 8 H, promargin toothless, two large denticles on retromargin. Legs yellow with darker annulation on distal part of femur, and whole tibia. Leg measurements: I 10.57 (2.74, 0.45, 3.07, 2.83, 1.48), II 8.82 (2.31, 0.45, 2.45, 2.39, 1.22), III 6.58 (1.84, 0.35, 1.75, 1.78, 0.86), IV 8.89 (2.59, 0.39, 2.40, 2.39, 1.12). Dorsal side of opisthosoma black with yellowish-gray wide marks scattered with numerous white small dots inside, lateral and ventral sides and spinnerets black. Palp as in Fig. 7 A – D. Tibia ~ 1.5 times longer than patella, one stocky rounded apophysis on retrolateral side, bearing a long seta. Cymbium with two well-developed retrolateral basal processes (RBP 1 − 2), RBP 1 hook-like, bent postero-retrolaterally with a ~ 130 ° angle, RBP 2 long, thin, and straight, headed retrolaterally. Paracymbium as in Fig. 7 E, sturdy, U-shaped; outer process (OP) elongated antero-dorsally, ending with two short, rounded prongs; two median processes (MP 1 – 2), MP 1 on outer border, blunt and stocky, MP 2 on internal border, triangular with a sharp tip; distal process (DP) hook-like, bent dorsally; ventral process (VT) wide and stocky. Embolic division as in Fig. 7 F – H. Fickert’s gland (FiG) clearly visible. Anterior radical process (ARP), rectangular in ventral view, headed antero-prolaterally. Lamella characteristica (LC) elongated, tread-like, basally wide, distally tapering. Posterior part of terminal apophysis with two processes (PTA 1 − 2), PTA 1 thin and long, headed anteriorly, ending fringed and transparent; PTA 2 massive, curved and protruding ventral-retrolaterally, ribbon-like with a longitudinal groove along its whole median line. Anterior part of terminal apophysis (ATA) hook-like, thick and sturdy. Median membrane (MM) fringed and transparent. Thumb of embolus (TH) sclerotized, lamellar-like. Embolus proper (EP) short, triangular. Redescription. Female. Habitus as in Fig. 8 G. Total length: 2.93, carapace 1.40 long, 1.08 wide. Carapace more oval than in male. Eyes measurements: AME = 0.08, ALE = 0.10, PME = 0.11, PLE = 0.11, AME – ALE = 0.10, ALE – PLE = 0.01, PME – PLE = 0.06. Clypeus 0.25 long. Chelicera with three large denticles on promargin and four small denticles on retromargin. Leg measurements as follows: I 8.73 (2.34, 0.45, 2.49, 2.27, 1.18), II 7.49 (2.06, 0.42, 2.12, 1.83, 1.06), III 6.74 (1.90, 0.35, 1.77, 1.87, 0.85), IV 7.78 (2.25, 0.42, 2.14, 1.86, 1.11). Dorsal pattern of opisthosoma more evident than in male. Other somatic characters as in male. Epigyne and vulva as in Fig. 8 A−D. Epigynal base (EB) wide and sturdy. Posterior median plate (PMP) ~ shaped as a wine glass in dorsal view, basal part wide then tapering. Scapus (SC) elongated, sturdy, approximately hook-like in lateral view, basal part protruding ventrally then curved posteriorly. Distal part of scapus (DS) recurved inward, arrow-like in dorsal view; lateral lobes of scapus (LL) well developed, protruding laterally and curved ventrally. Copulatory openings (CO) at base of LL. Fertilization grooves (FG) thin, comma-like. Copulatory grooves (CG) long and thin, starting from LL and following whole length of scapus, enlarging at basal part of scapus and coiling before reaching base of spermatheca. Spermatheca (S) small and round. Size variation. Male (n = 5): total length: 3.23 – 3.35, carapace length: 1.59 – 1.63, width: 1.27 – 1.35. Female (n = 5): total length: 2.31 – 2.93, carapace length: 1.19 – 1.40, width: 0.91 – 1.11.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF3E502FF4AFB7D376DF985.taxon	distribution	Distribution and ecology. Arcuphantes ashifuensis was previously known only for records from forest litter in the northern area of the Kyoto prefecture reported in the original description by Oi (1960). A single record from Tokyo reported by Shinkai (1969) likely refers to a misidentification with other Arcuphantes species. Herein, we report for the first time the species from subterranean environments in western Fukui Prefecture, approximately 10 km northeast of the type locality, thus confirming the distribution of this species as a probable endemism in northern Kansai (Fig. 28). Numerous individuals were observed spinning webs in wall crevices in the twilight and dark zones of the cave. Troglophilic species.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF3E502FF4AFB7D376DF985.taxon	discussion	Remarks. Oi (1960: 204) examined one adult male, one adult female, and two subadult males, designating the adult male as the holotype. However, only the female was described and illustrated in the paper. Herein, we describe the male for the first time and illustrate in detail both sexes based on newly collected adult individuals.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF6E503FF4AF92D376DFE5C.taxon	vernacular_names	(Japanese name: Rokusho-yamisaragumo ロクショヤミサラグモ)	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF6E503FF4AF92D376DFE5C.taxon	description	Figs 9 A – H, 10 A−F	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF6E503FF4AF92D376DFE5C.taxon	materials_examined	Material examined. JAPAN: Aichi Pref., 6 ♀, Toyohashi City, Susecho, Suse Ja-ana cave (DZƜ 蛇穴), deep and humid cave, 34.7970 ° N, 137.4859 ° E, 29. Sep. 2019, F. Ballarin & A. Tanikawa leg. (FBPC) ● 1 ♂, 2 ♀, same locality, 13. Jan. 2024, N. Kikuchi & T. Yoshida leg. (TMNH).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF6E503FF4AF92D376DFE5C.taxon	diagnosis	Diagnosis and description. See Saito (1992: 17, 18). Male total length: 2.39, carapace 1.29 long, 1.10 wide. Female total length: 2.44, carapace length: 1.13, width: 0.94. Male habitus as in Fig. 10 D, F; female habitus as in Fig. 10 E. Male palp as in Fig. 9 A – H, epigyne as in Fig. 10 A−C. Size variation. Female (n = 5): total length: 2.15 – 2.55, carapace length: 1.07 – 1.15, width: 0.82 – 0.95.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF6E503FF4AF92D376DFE5C.taxon	discussion	Remarks. Arcuphantes digitatus is known from several epigean records in Aichi and Shizuoka Prefectures, Honshu (Japan Spider Catalog 2025). Here we report the species for the first time from subterranean environments, in the twilight and transition zones of a natural cave in Aichi Prefecture (Fig. 28). Troglophilic species.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF4E50EFF4AFA6F31B2F93B.taxon	vernacular_names	(Japanese name: Tokushima-yamisaragumo トクシマヤミサラグモ)	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF4E50EFF4AFA6F31B2F93B.taxon	description	Figs 11 A – H, 12 A – F	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF4E50EFF4AFA6F31B2F93B.taxon	materials_examined	Material examined. JAPAN: Shikoku Is. Tokushima Pref., 3 ♂, 1 ♀, Tokushima City, Nyūta City, Konji, Konjiji temple (建ã Ḣ), narrow and dry tunnel dug in the cliff near the temple, 34.0277 ° N, 134.4292 ° E, 13. May. 2019, F. Ballarin & T. Yamasaki leg. (TKPM-AR 3608) ● 1 ♂, 3 ♀, Naka-gun, Naka City, Nagayasu, Himise-do cave (Ƌ AEȒ), a short cave along the road with a deep sinkhole, 33.8079 ° N, 134.3439 ° E, 14. May. 2019, F. Ballarin & T. Yamasaki leg. (FBPC).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF4E50EFF4AFA6F31B2F93B.taxon	diagnosis	Diagnosis and description. See Ono & Saito (2001: 192 − 194). Male total length: 2.10, carapace length: 1.06, width: 0.94; female total length: 2.17, carapace length: 0.97, width: 0.86. Male habitus as in Fig. 12 D, F; female habitus as in Fig. 12 E. Male palp as in Fig. 11 A – H, epigyne as in Fig. 12 A−C. Size variation. Male (n = 3): total length: 2.08 – 2.23, carapace length: 1.00 – 1.09, width: 0.91 – 0.97. Female (n = 3): total length: 2.13 – 2.21, carapace length: 0.94 – 1.06, width: 0.80 – 0.86.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF4E50EFF4AFA6F31B2F93B.taxon	discussion	Remarks. Arcuphantes elephantis is known for several epigean records, all from Tokushima Prefecture in Shikoku (Japan Spider Catalog 2025). This species was reported for the first time from subterranean environments only very recently (Suzuki, 2025). Here we further confirm its presence in hypogean habitats and we report additional records. A. elephantis was collected by us at the entrance, twilight, and transition zones of both natural caves and artificial tunnels in Tokushima Prefecture (Fig. 28). Troglophilic species.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFFAE50CFF4AF8B6328AFC85.taxon	vernacular_names	(Japanese name: Fuji-yamisaragumo フジヤミサラグモ)	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFFAE50CFF4AF8B6328AFC85.taxon	description	Figs 13 A – H, 14 A – F	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFFAE50CFF4AF8B6328AFC85.taxon	materials_examined	Material examined. JAPAN: Shizuoka Pref., 1 ♂, 5 ♀ (topotypes), Fujinomiya City, Hitoana, Hitoana cave (人 穴), wide and humid lava cave, 695 m, 35.3616 ° N, 138.5911 ° E, 1. Dec. 2022, F. Ballarin leg. (FBPC) ● 5 ♀, Suyama City, Jurigi Ice Cave (十ƤÌ氷穴), cold lava cave, 923 m, 35.2649 ° N, 138.7990 ° E, 2. Dec. 2022, F. Ballarin leg. (FBPC); ● 1 ♀, Izu Peninsula, Izu City, Yagashima, scree along a narrow valley, 770 m, 34.8302 ° N, 138.9322 ° E, 22. Feb. 2026, F. Ballarin leg. (FBPC).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFFAE50CFF4AF8B6328AFC85.taxon	diagnosis	Diagnosis and description. See Yaginuma (1972: 301 − 303). Male total length: 2.37, carapace length: 1.03, width: 0.92. Female total length: 2.29, carapace length: 1.02, width: 092. Male habitus as in Fig. 14 D, F; female habitus as in Fig. 14 E. Male palp as in Fig. 13 A – H, epigyne as in Fig. 14 A−C. Size variation. Female (n = 5): total length: 1.75 – 2.38, carapace length: 0.99 – 1.15, width: 0.82 – 0.99.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFFAE50CFF4AF8B6328AFC85.taxon	distribution	Distribution and habitat. Arcuphantes fujiensis is known for sparse records in central Japan, in Ibaraki, Tochigi, Kanagawa, Yamanashi, and Shizuoka Prefectures, Honshu (Japan Spider Catalog 2025) from both epigean and hypogean habitats. Records from Ibaraki and Tochigi Prefectures are doubtful and possibly refer to other similar species like A. uenoi (Y. Suzuki, in litteris). Based on the illustrated copulatory organs, previous records of A. delicatus (Chikuni, 1955) from Shizuoka Prefecture (e. g., Suzuki 2018) also refer to A. fujiensis. We collected numerous individuals on wall crevices and on artificial structures within the twilight and transition zones of lava caves in the surroundings of Mt. Fuji, as well as among void spaces in deep scree deposits (Fig. 28). Troglophilic species.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF9E50DFF4AFF1830D5FC87.taxon	vernacular_names	(Japanese name: Hikosan-yamisaragumo ヒコサンヤミサラグモ)	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF9E50DFF4AFF1830D5FC87.taxon	description	Figs 15 A – H, 16 A−F	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF9E50DFF4AFF1830D5FC87.taxon	materials_examined	Material examined. JAPAN: Kyushu Is.: Fukuoka Pref., 3 ♂, 8 ♀, Kitakyushu, Hiraodai, Mejirodô Cave (Ʊ 白 鍾ÂȒ), long and humid cave with several large stones, 33.76123 ° N, 130.90692 ° E, 474 m, 4. Aug. 2022, F. Ballarin & A. Tanikawa leg. (FBPC).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF9E50DFF4AFF1830D5FC87.taxon	diagnosis	Diagnosis and description. See Saito (1992: 16, 17). Male total length: 2.09, carapace length: 1.01, width: 0.92. Female total length: 2.20, carapace length: 1.06, width: 0.91. Male habitus as in Fig. 16 D, F; female habitus as in Fig. 16 E. Male palp as in Fig. 15 A – H, epigyne as in Fig. 16 A−C. Size variation. Male (n = 3): total length: 2.09 – 2.30, carapace length: 1.01 – 1.14, width: 0.91 – 0.96. Female (n = 5): total length: 1.75 – 2.46, carapace length: 0.93 – 1.11, width: 0.75 – 0.94.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF9E50DFF4AFF1830D5FC87.taxon	distribution	Distribution and ecology. Arcuphantes hikosanensis is currently known only from a few epigean records in Fukuoka, Kumamoto, and Ōita Prefectures in central-north Kyushu (Japan Spider Catalog 2025). We report the species for the first time from subterranean environments, in a new locality from Fukuoka Prefecture, approximately 20 km north of the type locality (Fig. 28). We observed several individuals spinning webs in wall crevices and under stones in the twilight, transition, and dark zones	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF9E536FF4AFC2B362EFBE1.taxon	vernacular_names	(Japanese name: Ise-yamisaragumo Kセヤミサラグモ)	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF9E536FF4AFC2B362EFBE1.taxon	description	Figs 17 A – H, 18 A – H	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF9E536FF4AFC2B362EFBE1.taxon	materials_examined	Material examined. Holotype. ♂ JAPAN: Mie Pref., Ise City, Yamochicho, Ichigodo cave (OiÄŦȒ), narrow and tortuous cave, 34.4099 ° N, 136.7100 ° E, 4. Oct. 2019, F. Ballarin & A. Tanikawa leg. (NSMT- 26848). Paratypes. JAPAN: Mie Pref., 4 ♂, 7 ♀, same data as the holotype (2 ♂, 4 ♀ NSMT- 26849; 2 ♂, 3 ♀ MNHAHB 6 - 000453) ● 1 ♂, 1 ♀, Ise City, Kirihara, nameless small cave, 305 m, 34.3865 ° N, 136.7306 ° E, 29. Jul. 2024 T. Nagai & Y. Aoyagi leg. (NSMT- 26850) ● 2 ♂, 10 ♀, Taiki Town, Aso, Aso no Kaza-ana cave (阿曽OĀ穴), 178 m, 34.3355 ° N, 136.4438 ° E, 30. Jul. 2024, F. Ballarin leg. (1 ♂, 5 ♀ TKPM-AR 3607; 1 ♂, 5 ♀ MSNVR-Ar 054 – 059) ● 1 ♀, same locality, nameless small cave with small creek inside, 235 m, 34.3250 ° N, 136.4039 ° E, 29. Jul. 2024, F. Ballarin leg. (FBPC- 2024001) ● 2 ♂, 6 ♀, Taiki Town, Eikai, Kōmori kaza-ana cave (コウモリĀ 穴), 141 m, 34.3519 ° N, 136.4872 ° E, 29. Jul. 2024, F. Ballarin leg. (1 ♂, 3 ♀ FBPC- 2024002; 1 ♂, 3 ♀ MNHAH-B 6 - 000454)	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF9E536FF4AFC2B362EFBE1.taxon	etymology	Etymology. The species name is derived from Ise City (伊 ẍṁ), which area includes most of the localities where the new species was found, including the type locality cave.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF9E536FF4AFC2B362EFBE1.taxon	diagnosis	Diagnosis. Arcuphantes iseensis sp. nov. is closely related to the recently described A. shiozakii Ono, Ihara & Nakano, 2024 and A. yakiyama Ihara & Nakano, 2024. Male of the new species can be distinguished from male of A. shiozakii and A. yakiyama by the different shape of the posterior part of the terminal apophysis, having a thicker and straighter projection (vs slimmer and more curved); the thinner and rounded posterior part of radix with a small, ribbon-like lamella characteristica (LC) [vs posterior part of radix wider with a thicker and bulkier, hook-like LC (= pseudolamella in the original description)]; and a curved lamellar extension (vs. straighter). Additionally, it can be distinguished by the different shape of the paracymbium, having a distal process short, strongly curved and with a blunt tip (vs. longer, straighter and ending sharper), a bulkier median process 1 (MP 1) (vs. less bulky), and a median process 2 (MP 2) with a thinner and sharper tip curved dorsally [vs MP 2 (= apophysis of paracymbium in the original description) lacking in A. shiozakii or S-shaped and with a wider tip in A. yakiyama)] (cf. Fig 17 A, B, E – H vs Ono et al. 2024: figs 3 A – D, 4 A – D). Female of the new species can be easily distinguished from female of A. shiozakii and A. yakiyama by the different shapes of the posterior median plate, wider and lacking a median bottleneck and flat in dorsal view and non-protruding in lateral view (vs having a strong median bottleneck and strongly protruding in the other two species) (cf. Fig. 18 A – C vs Ono et al. 2024: figs 3 E – G, 4 E – G).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF9E536FF4AFC2B362EFBE1.taxon	description	Description. Male (holotype). Habitus as in Fig. 18 G. Total length: 2.36, carapace 1.20 long, 1.04 wide. Carapace round, uniformly dark brown. Chelicera and maxillae of same color. Labium and sternum black brown. Cephalic area as in Fig. 18 I. Eyes well developed. Eyes measurements: AME = 0.07; ALE = 0.1, PME = 0.1, PLE = 0.1, AME – ALE = 0.07, ALE – PLE = 0.01, PME – PLE = 0.04. Clypeus 0.22 long. Chelicera as in Fig. 18 E, promargin toothless, two large denticles on retromargin. Legs yellowish with darker annulation on distal part of femur, and whole tibia. Leg measurements: I 7.31 (1.98, 0.36, 2.07, 1.87, 1.03), II 6.29 (1.70, 0.34, 1.73, 1.58, 0.94), III 4.65 (1.34, 0.28, 1.20, 1.21, 0.62), IV 5.93 (1.43, 0.30, 1.70, 1.65, 0.85). Dorsal side of opisthosoma dark grey with lines of whitish rounded marks scattered with numerous white small dots inside; lateral and ventral sides and spinnerets black. Palp as in Fig. 17 A – D. Tibia ~ as long as patella, with tuft of thick setae on dorsal side. Cymbium with one well-developed retrolateral basal process (RBP), bent retrolaterally with a 90 ° angle. Paracymbium as in Fig. 17 E, wide and ventrally elongated; basal part with two blunt and stocky outer processes (OP 1 – 2); two median processes (MP 1 − 2), MP 1 trapezoidal, thick and wide, headed retrolaterally, MP 2 tread-like, transparent, thin and long, curved dorsally; distal process (DP) blunt, hook-like, headed ventro-retrolaterally. Embolic division as in Fig. 17 F – H. Fickert’s gland (FiG) clearly visible. Posterior part of radix protruding dorsally; lamella characteristica (LC) transparent, short, flat and wide; lamellar extension (LE) thread-like, curved anteriorly. Prolateral median process of radix (PMR) short, sturdy; anterior radical process (ARP) massive and sturdy, protruding dorsally, ending with a sharp, transparent tip. Posterior part of terminal apophysis (PTA) developed as a massive, strongly sclerotized straight process, protruding antero-dorsally, with a lobated ventral process; Anterior part of terminal apophysis (ATA) massive, elongated anteriorly, lobated in ventral view, with transparent membrane on dorsal border. Median membrane (MM) ribbon-like, fringed and transparent. Embolus (E) almost completely hidden by ATA; embolus proper (EP) short, triangular. Description. Female (one of the paratypes). Habitus as in Fig. 18 H. Total length: 2.18, carapace 0.89 long, 0.78 wide. Carapace oval. Eyes measurements: AME = 0.05, ALE = 0.09, PME = 0.08, PLE = 0.09, AME – ALE = 0.06, ALE – PLE = 0.01, PME – PLE = 0.03. Clypeus 0.19 long. Chelicera as in Fig. 18 F, with three large denticles on promargin and four small denticles on retromargin. Leg measurements as follows: I 5.76 (1.52, 0.32, 1.56, 1.45, 0.91), II 4.96 (1.34, 0.31, 1.30, 1.25, 0.76), III 3.76 (1.08, 0.29, 0.90, 0.94, 0.55), IV 4.94 (1.40, 0.30, 1.27, 1.23, 0.74). Dorsal pattern of opisthosoma more evident than in male. Other somatic characters as in male. Epigyne and vulva as in Fig. 18 A – D. Epigynal base (EB) triangular, wide and sturdy. Posterior median plate (PMP) elongated, ~ rectangular in dorsal view. Scapus (SC) elongated, coiled internally on itself in a tight spiral; distal part of scapus (DS) rounded, recurved inward. Copulatory openings (CO) at base of DS. Fertilization grooves (FG) thin, comma-like. Copulatory grooves (CG) long and thin, starting from DS and following whole length of SC, reaching base of spermatheca with a sinuous trait. Spermatheca (S) wide, round. Size variation. Male (n = 5): total length: 2.01 – 2.56, carapace length: 1.14 – 1.21, width: 0.99 – 1.04. Female (n = 5): total length: 2.05 – 2.18, carapace length: 0.84 – 0.95, width: 0.78 – 0.83.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFF9E536FF4AFC2B362EFBE1.taxon	distribution	Distribution and ecology. Arcuphantes iseensis sp. nov. was found near the entrance, twilight, and transition zones in several caves in the south-eastern area of the Mie Prefecture (Fig. 28). We observed numerous individuals spinning webs in wall crevices or in empty spaces among rocks on the floor. Currently, no epigean records are known; however, due to the absence of morphological adaptation to subterranean life, we cannot exclude that the species may also inhabit dark and humid epigean environments. Troglophilic species.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC2E535FF4AFB0930FDFA49.taxon	vernacular_names	(Japanese name: Bungo-horayamisaragumo ブンゴホラヤミサラグモ)	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC2E535FF4AFB0930FDFA49.taxon	description	Figs 19 A – H, 20 A – H	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC2E535FF4AFB0930FDFA49.taxon	materials_examined	Material examined. JAPAN: Kyushu: Ōita Pref., 2 ♂, 3 ♀, Usuki City, Notsumachi Oaza Tomari, Hakusan Shrine (白Ɯ神社), nameless cave, 367 m, 33.0129 ° N, 131.7446 ° E, large cave with large scree near the entrance, 3. Aug. 2022, F. Ballarin & A. Tanikawa leg. (1 ♂, 2 ♀ NSMT, 1 ♂, 1 ♀ FBPC).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC2E535FF4AFB0930FDFA49.taxon	diagnosis	Diagnosis. Males of A. longissimus can be easily distinguished from males of any other Japanese Arcuphantes by the distinctive shape of the palp having an elongated radix, a thread-like posterior part of the terminal apophysis, a massive hook-like anterior radical process, and the presence of two spurs on the posterior part of radix, all differently shaped in the other species. The uniquely shaped apophyses of the paracymbium also help an easy identification. Females are easily distinguished by the shape of the scapus of the epigyne, extremely elongated and thin with well-developed lateral projections (LP) (cf. Figs 19 A−H, 20 A−D vs Ono et al. 2009: figs 726 – 797).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC2E535FF4AFB0930FDFA49.taxon	description	Description. Male. Habitus as in Fig. 20 F. Total length: 2.06, carapace 1.00 long, 0.85 wide. Carapace rounded, uniformly dark brown with darker, faint radial bands. Chelicera and maxillae of same color. Labium and sternum black brown. Cephalic area as in Fig. 20 E. Eyes well developed, silver with black basal area. Eyes measurements: AME = 0.07; ALE = 0.09, PME = 0.09, PLE = 0.09, AME – ALE = 0.06, ALE – PLE = 0.01, PME – PLE = 0.05. Clypeus 0.17 long. Chelicera as in Fig. 20 H, promargin toothless, three denticles on retromargin, two sharp and one sturdy. Legs yellow with faint darker annulation on distal part of femur, and whole tibia. Leg measurements: I 6.46 (1.66, 0.30, 1.84, 1.69, 0.97), II 5.40 (1.42, 0.29, 1.44, 1.45, 0.80), III 4.02 (1.14, 0.27, 1.02, 1.02, 0.57), IV 5.39 (1.54, 0.23, 1.47, 1.41, 0.74). Dorsal side of opisthosoma dark grey with series of whitish marks along longitudinal line. Lateral and ventral sides and spinnerets dark grey. Palp as in Fig. 19 A – D. Tibia short, ~ as long as patella, with one dorsal long seta. Cymbium with one well-developed, thorn-like, retrolateral basal process (RBP), curved retrolaterally, ending with sharp tip. Paracymbium as in Fig. 19 E, wide and elongated anteriorly; one short, thorn-like posterior process (PP); two outer processes (OP 1 – 2), OP 1 massive, distally widened and bent ventrally, with a small, triangular tip pointing anteriorly; OP 2 long and thin, extending from the dorsal side of OP 1, curved anteriorly; two median processes (MP 1 – 2), MP 1 on internal border, small, triangular, MP 2 large, approximately triangular, bearing one small triangular process at its base, ending with a rounded, lobated tip; distal process (DP) blunt, ending with a rounded tip curved anteriorly. Embolic division as in Fig. 19 F – H, strongly elongated. Fickert’s gland not visible. Posterior part of radix, sturdy, with two sclerotized, triangular processes headed posteriorly; prolateral median process (PMR) short, sturdy, sclerotized; anterior radical process (ARP) massive, hook-like, bent posteriorly, ending sharp. Lamella characteristica (LC) triangular, stocky, bent antero-dorsally, ending fringed and transparent; posterior part of terminal apophysis (PTA) thread-like, Sshaped, headed antero-dorsally; anterior part of terminal apophysis (ATA) shaped as two wide, lobated processes. Median membrane (MM) long, fringed and transparent. Embolus (E) small, triangular, covered by ATA, visible only when embolic division is observed dorsally. Redescription. Female. Habitus as in Fig. 20 G. Total length: 2.10, carapace 0.93 long, 0.84 wide. Carapace more oval than male. Eyes measurements: AME = 0.05, ALE = 0.08, PME = 0.08, PLE = 0.08, AME – ALE = 0.05, ALE – PLE = 0.05, PME – PLE = 0.05. Clypeus 0.16 long. Chelicera with three large denticles on promargin and three – four small denticles on retromargin. Leg measurements as follows: I 5.81 (1.51, 0.31, 1.63, 1.46, 0.90), II 4.92 (1.46, 0.27, 1.26, 1.25, 0.68), III 3.58 (1.06, 0.26, 0.91, 0.87, 0.48), IV 4.86 (1.34, 0.30, 1.28, 1.24, 0.70). Dorsal pattern of opisthosoma more evident than in male. Other somatic characters as in male. Epigyne and vulva as in Fig. 20 A−D. Epigynal base (EB) wide. Posterior median plate (PMP) small, heartshaped in dorsal view; lateral walls (LW) forming two well-developed lateral projections clearly visible when epigyne is observed laterally. Scapus (SC) extremely elongated and thin, basal part S-shaped, continuing coiled back on itself with a 0 - shape in lateral view. Distal part of scapus (DS) elongated and rounded, leaning on internal side of scapus. Copulatory openings (CO) at lateral sides of tip of DS. Fertilization grooves (FG) thin, comma-like. Copulatory grooves (CG) long and thin, starting from tip of DS and following whole length of SC, enlarging at its basal part, reaching basal part of spermatheca with a convoluted course. Spermatheca (S) small and round. Size variation. Male (n = 2): total length: 1.93 – 2.06, carapace length: 1.00 – 1.06, width: 0.85 – 0.96. Female (n = 3): total length: 2.10 – 2.18, carapace length: 0.92 – 0.98, width: 0.83 – 0.84.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC2E535FF4AFB0930FDFA49.taxon	distribution	Distribution and ecology. Arcuphantes longissimus is known only for sparse records in both epigean and hypogean environments in Yamaguchi and Ōita Prefectures in Western Japan (Japan Spider catalog 2025). We observed individuals spinning webs in the empty spaces among large stones on the floor in the twilight zone of a cave in Ōita Prefecture (Fig. 28). The relatively high number of records from caves may suggest that this species has a stronger affinity for subterranean habitats than other Arcuphantes species. Troglophilic species.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC2E535FF4AFB0930FDFA49.taxon	discussion	Remarks. Arcuphantes longissimus was previously known for female specimens. Here, we describe and illustrate in detail the male for the first time.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC1E530FF4AFA6130ACFC38.taxon	vernacular_names	(Japanese name: Tama-yamisaragumo タマヤミサラグモ)	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC1E530FF4AFA6130ACFC38.taxon	description	Figs 21 A−H, 22 A−F	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC1E530FF4AFA6130ACFC38.taxon	materials_examined	Material examined. JAPAN: Tokyo Pref., 4 ♂, 3 ♀, Hachioji City, narrow valley along trail to Hachioji castle ruins, 35.6465 ° N, 139.2517 ° E, deep humid scree near a temporally creek, 31. May. 2021, F. Ballarin leg. (FBPC) ● Kanagawa Pref., 2 ♂, 6 ♀, Hakone, Yumoto, Shiraishi-jizo-no-ana cave (白Ƃ地ÑO穴), 160 m, 35.2340 ° N, 139.10338 ° E, 24. Oct. 2021, F. Ballarin leg. (FBPC).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC1E530FF4AFA6130ACFC38.taxon	description	Description. Male. Habitus as in Fig. 22 D. Total length: 2.41, carapace 1.26 long, 1.10 wide. Carapace rounded, uniformly dark brown with darker, faint radial bands. Chelicera and maxillae of same color. Labium and sternum black brown. Cephalic area as in Fig. 22 F. Eyes well developed, silver with black basal area. Eyes measurements: AME = 0.05; ALE = 0.08, PME = 0.09, PLE = 0.08, AME – ALE = 0.07, ALE – PLE = 0.01, PME – PLE = 0.06. Clypeus 0.24 long. Promargin of chelicera toothless, two denticles on retromargin. Legs yellow with dark brown annulation on distal tip of femur, and whole tibia. Leg measurements: I 7.33 (1.92, 0.32, 2.05, 2.02, 1.02), II 6.21 (1.72, 0.30, 1.70, 1.66, 0.83), III 4.59 (1.32, 0.25, 1.16, 1.23, 0.63), IV 6.18 (1.80, 0.30, 1.65, 1.64, 0.79). Dorsal side of opisthosoma dark gray with wide central faint lighter mark and couple of sides and posterior whitish marks. Lateral and ventral sides of opisthosoma and spinnerets dark grey. Palp as in Fig. 21 A – D. Tibia rounded, ~ as long as patella, lacking any apophysis, bearing a long retrolateral seta. Cymbium with one retrolateral basal process (RBP), short and straight, ending with a rounded tip. Paracymbium as in Fig. 21 E, short and sturdy; outer process (OP) elongated dorsally, ending with a rounded tip; two median processes (MP 1 – 2), MP 1 thorn-like, short and pointed, MP 2 long and lobated, curved antero-dorsally, ending with a rounded tip; distal process (DP) small, triangular, ending sharp. Embolic division as in Fig. 21 F – H. Fickert’s gland (FiG) clearly visible, accompanied by a secondary swelling; sperm duct long and convoluted. Anterior radical process (ARP), sturdy, lobated, expanded dorsally, ending with a rounded tip slightly curved posteriorly. Lamella characteristica (LC) finger-like, short and thin, headed dorsal-posteriorly. Posterior part of terminal apophysis (PTA) thin, spur-like; anterior part of terminal apophysis (ATA) elongate anteriorly, with two short, lobated processes ventrally, bearing a fringed, transparent membrane on dorsal border. Median membrane (MM) fringed and transparent. Thumb of embolus (TH) short and lobated. Embolus proper (EP) short, triangular. Redescription. Female. Habitus as in Fig. 22 D. Total length: 2.24, carapace 0.96 long, 0.84 wide. Carapace more oval than male. Eyes measurements: AME = 0.05, ALE = 0.08, PME = 0.08, PLE = 0.08, AME – ALE = 0.05, ALE – PLE = 0.01, PME – PLE = 0.05. Clypeus 0.20 long. Chelicera with three large denticles on promargin and four small denticles on retromargin. Leg measurements as follows: I 6.24 (1.66, 0.31, 1.74, 1.60, 0.93), II 5.36 (1.50, 0.31, 1.45, 1.33, 0.77), III 3.75 (1.14, 0.27, 0.97, 0.84, 0.53), IV 6.77 (1.54, 0.30, 1.97, 1.98, 0.98). Dorsal pattern of opisthosoma more evident than in male. Other somatic characters as in male. Epigyne as in Fig. 22 A−C. Epigynal base (EB) wide. Posterior median plate (PMP) ~ trapezoidal in dorsal view. Scapus (S) short and sturdy, curved interiorly on itself. Distal part of scapus (DS) recurved inward, enlarged, ~ triangular in dorsal view. Copulatory openings (CO) at basal side of DS. Fertilization grooves (FG) thin, comma-like. Copulatory grooves (CG) long, following the length of SC, enlarging at basal part of SC and reaching base of spermatheca with a coil. Spermatheca (S) small, bean-shaped. See also Oi (1960: 202, 203). Size variation. Male (n = 5): total length: 2.40 – 2.48, carapace length: 1.23 – 1.27, width: 1.04 – 1.11. Female (n = 5): total length: 2.21 – 2.39, carapace length: 0.98 – 1.07, width: 0.88 – 0.91.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC1E530FF4AFA6130ACFC38.taxon	distribution	Distribution and ecology. Arcuphantes tamaensis is distributed in the Kantō and Chūbu Regions in central Japan with records from Ibaraki, Saitama, Chiba, Tokyo, Kanagawa, Niigata, and Shizuoka Prefectures (Japan Spider catalog 2025). However, the presence of the species in northern Kantō (Ibaraki) and Niigata Prefecture remain to be verified, being based only on isolated and old records that may refer to misidentifications of other similar species (Y. Suzuki, in litteris). Arcuphantes tamaensis is known to exploit both epigean and hypogean habitats. We collected it along cave walls in the twilight and transition zones of natural caves and in rock gaps in deep screes in Kantō area (Fig. 28). Troglophilic species.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC1E530FF4AFA6130ACFC38.taxon	discussion	Remarks. This species was originally described by Oi (1960) based solely on females. Later, Yaginuma (1986) and Ono et al (2009) provided simplified drawings of the male palp, without a description. Herein, we redescribe both sexes and provide detailed illustrations of the diagnostic characters based on specimens from the Hachioji area, approximately 20 km southeast of the type locality.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC4E53EFF4AFBB13093FBE1.taxon	vernacular_names	(Japanese name: Hora-yamisaragumo ホラヤミサラグモ)	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC4E53EFF4AFBB13093FBE1.taxon	description	Fig. 23 A−J	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC4E53EFF4AFBB13093FBE1.taxon	materials_examined	Material examined. JAPAN: Shiga Pref., 1 ♂, 1 ♀ subadult (topotype), Taga City, Kawachi, Kawachi no Kaza-ana (河HĀ穴), 35.2507 ° N, 136.3537 ° E, inside deep cracks among rocks, 2. Oct. 2019, F. Ballarin & A. Tanikawa leg. (FBPC).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC4E53EFF4AFBB13093FBE1.taxon	diagnosis	Diagnosis. Males and females of A. troglodytarum can be distinguished from those of other Japanese Arcuphantes species by the lighter color and the lack of a dorsal pattern on opisthosoma. Additionally, males of this species can be identified by the unique shape of the posterior part of the terminal apophysis of radix, short and sturdy with two lobated projections protruding anteriorly and ventro-retrolaterally; by the shape of the lamella characteristica, reduced to a small spur; and by the convoluted sperm duct which course is visible by transparency (cf. Fig. 23 A – J vs Ono et al. 2009: figs 726 – 797).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC4E53EFF4AFBB13093FBE1.taxon	description	Redescription. Male. Habitus as in Fig. 23 I. Total length: 2.52, carapace 1.16 long, 1.08 wide. Carapace rounded, uniformly yellowish with faint darker radial bands. Chelicera and maxillae of same color. Labium and sternum dark brown. Cephalic area as in Fig. 23 J. Eyes slightly reduced, silver with black basal area. Eyes measurements: AME = 0.05; ALE = 0.06, PME = 0.07, PLE = 0.07, AME – ALE = 0.07, ALE – PLE = 0.01, PME – PLE = 0.05. Clypeus 0.29 long. Promargin of chelicera toothless, two denticles and one small triangular spur on retromargin. Legs uniformly yellow. Leg measurements: I 8.99 (2.44, 0.40, 2.58, 2.33, 1.24), II 8.12 (2.27, 0.38, 2.30, 2.06, 1.11), III 5.96 (1.77, 0.34, 1.56, 1.50, 0.79), IV 8.09 (2.53, 0.34, 2.14, 2.05, 1.03). Opisthosoma uniformly light grey with faint darker longitudinal and posterior areas lacking any pattern; spinnerets whitish. Palp as in Figs 23 A – D. Tibia rounded, ~ as long as patella, lacking any apophysis. Cymbium with one wide retrolateral basal process (RBP), short, stocky, and rounded. Paracymbium as in Fig. 23 E, short and sturdy, Ushaped; outer process (OP) lobated, with a round tip; two small median processes (MP 1 – 2), both thorn-like and pointed; distal process (DP) elongated, slightly curved dorsally, ending with a rounded tip. Embolic division as in Fig. 23 F – H. Fickert’s gland (FiG) clearly visible; sperm duct long and convoluted. Anterior radical process (ARP), sturdy, lobated, protruding dorsally, ending with a wide, rounded tip. Lamella characteristica (LC) short, spur-like, headed dorsally. Posterior part of terminal apophysis (PTA) sturdy and strongly sclerotized, with two lobated projections protruding anteriorly and ventro-retrolaterally; anterior part of terminal apophysis (ATA) wide and short, slightly protruding ventro-retrolaterally; membrane of terminal apophysis (MTA) transparent, lobated. Median membrane (MM) fringed and transparent. Thumb of embolus (TH) short and lobated. Embolus proper (EP) short, triangular. Female. See Oi (1960: 204, 205). The subadult female collected by us shows a very light coloration and the same pattern of opisthosoma as reported in the original description.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC4E53EFF4AFBB13093FBE1.taxon	distribution	Distribution and ecology. Arcuphantes troglodytarum is known exclusively from subterranean habitats from few records in type locality caves Same no Kaza-ana (ẂƱĀ 穴) and Kawachi no Kaza-ana (河HĀ穴) in Shiga Prefecture (Japan Spider Catalog 2025, Fig. 28). In our survey we could collect only a single male and a subadult female suggesting that the species might be relatively rare. Arcuphantes troglodytarum does not exhibit extreme morphological adaptations, yet it maintains a certain degree of adaptations to the subterranean life including partial depigmentation, the absence of a dorsal pattern, elongated legs, and slight eye reduction. Based on these characteristics we consider the species possibly troglobitic although its ecology requires further investigation.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFC4E53EFF4AFBB13093FBE1.taxon	discussion	Remarks. Arcuphantes troglodytarum was previously known only from the original description by Oi (1960), based on a single male and female collected from two different caves (approximately 5 km from each other) in eastern Shiga Prefecture (Fig. 28), both designated by the author as the type locality of the species. The original description primarily focused on the female, while the description and illustrations of the male were limited to the palp, lacking details and body measurements. Here, we redescribe and provide detailed illustrations of the males based on a specimen collected from the type locality.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFCAE53FFF4AFB413008FC89.taxon	type_taxon	Type species. Erigone convexa Westring, 1851 from Sweden.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFCAE53FFF4AFB413008FC89.taxon	discussion	Remarks on genus Porrhomma in Japan. Porrhomma Simon, 1884 is a relatively small genus with a Holarctic distribution and a rather uniform somatic and genital morphology, comprising 26 accepted species to date (World Spider Catalog 2026). In Japan, four species are currently recorded: P. montanum Jackson, 1913; P. pygmaeum (Blackwall, 1834); P. ohkawai Saito, 1977; and P. rakanum Yaginuma & Saito, 1981. The latter two species are endemic to single cave systems in Japan and exhibit marked morphological adaptations to the subterranean lifestyle, including strong eye degeneration, depigmentation, and elongation of the legs (Shinkai et al. 2024, World Spider Catalog 2026). According to Růžička (2018), P. ohkawai and P. rakanum belong to the P. magnum group, a possibly monophyletic group of East Asian species that also includes P. longjiangense Zhu & Wang, 1983 from the Russian Far East and northeastern China, and P. magnum Tanasevitch, 2012 from southern Russia and northern Kazakhstan (Růžička 2018, World Spider Catalog 2026). In this work, we report an additional Japanese troglobitic Porrhomma species, which clearly shares both the diagnostic characters of the P. magnum group and morphological adaptations to subterranean life. For comparative purposes, we also illustrate P. rakanum based on specimens from its type locality cave. P. ohkawai remains known only from a few samples collected in a single cave system in Tochigi Prefecture and has not been recorded or re-illustrated since its original description by Saito (1977 a, b). An epigean record of P. cf. ohkawai based on a single female from Hyogo Prefecture (Yamamoto 2017) was examined and confirmed by us to be a misidentification of a different linyphiid genus. A similar epigean record from Mt. Sengenrei in Tokyo Prefecture, also based on females (Shinkai 2021), remains unconfirmed. However, given the difficulty in identifying females of Porrhomma species, the geographic distance from the original type locality, and the troglobitic habits of the species, this record is also likely a misidentification. The discovery of a new troglobitic species reported herein strengthens the idea that all the known endemic Japanese Porrhomma species are strictly cave-dwelling and highly endemic, being known from single caves. Accordingly, they represent good candidates for inclusion in local or national Red Lists and cave conservation projects. However, our preliminary molecular analysis also reveals low genetic distances between P. rakanum and P. niimiensis sp. nov. This occurs despite their differences in internal genital morphology and the apparent absence of gene flow, given the geographic distance between the respective caves and the presence of the Seto Inland Sea separating them. The limited genetic variation may suggest a recent subterranean colonization and rapid speciation event from a common, more widely distributed ancestor. Such a scenario, which deserves further investigation, could be linked to the relatively recent final formation of the Seto Inland Sea, following sea-level rise during the early to middle Holocene (Chujo et al. 2004; Yasuhara 2008) and the consequent isolation of previously connected populations. It is also possible that additional, yet undiscovered Porrhomma species belonging to the magnum group exist in other Japanese cave systems. For instance, we recently collected another troglobitic Porrhomma species from a cave in Gifu Prefecture, more than 300 km northeast of the type locality cave of P. niimiensis sp. nov. The single available female specimen does not allow us to confirm it as a distinct new species with confidence and our molecular analysis also suggests low genetic divergence (Table 4). Nevertheless, a preliminary morphological examination suggests potential differences in the vulval structure compared to other known species of the P. magnum group. These findings suggest the possibility of a still unexplored, wider diversity in the P. magnum group in Japan, coupled with an unusual low genetic divergence even among populations from distant caves with no apparent gene flow, a topic which warrants further study.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFCBE53FFF4AFC7D328AF936.taxon	vernacular_names	(Japanese name: Rakan-horaanasaragumo ラカンホラアナサラグモ)	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFCBE53FFF4AFC7D328AF936.taxon	description	Figs 24 A – E, 25 G, H	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFCBE53FFF4AFC7D328AF936.taxon	materials_examined	Material examined. JAPAN; Shikoku, Ehime Pref.: 5 ♂, 7 ♀ (topotypes) Seiyo City, Nomura-chō, Komatsu, Rakan-ana cave (Ḇae 穴), long and humid horizontal cave, 33.4889 ° N, 132.8373 ° E, 21. May. 2019, F. Ballarin & T. Yamasaki leg. (FBPC).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFCBE53FFF4AFC7D328AF936.taxon	diagnosis	Diagnosis and description. See Yaginuma & Saito (1981: 34 – 35) and Růžička (2018: 58). Male total length: 1.82, carapace length: 0.81, width: 0.64; female total length: 1.90, carapace length: 0.86, width: 0.66. Male habitus as in Fig. 24 D; female habitus as in Fig. 24 E. Embolic division of male palp as in Fig. 24 C, epigyne as in Fig. 24 A, B. Size variation. Male (n = 5): total length: 1.72 – 1.85, carapace length: 0.81 – 0.83, width: 0.64 – 0.65. Female (n = 5): total length: 1.88 – 1.91, carapace length: 0.82 – 0.88, width: 0.61 – 0.68.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFCBE53FFF4AFC7D328AF936.taxon	discussion	Remarks. Porrhomma rakanum is known exclusively from the type locality cave (Fig. 28). We observed a relatively large population in the dark zone of the cave. To facilitate the comparison with other Porrhomma species of the magnum group, we illustrate additional details of the copulatory organs of topotype specimens. Troglobitic species.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFCBE53BFF4AF8A431EAFD7D.taxon	vernacular_names	(Japanese name: niimi-horaanasaragumo ニKミホラアナサラグモ)	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFCBE53BFF4AF8A431EAFD7D.taxon	description	Fig. 25 A – F	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFCBE53BFF4AF8A431EAFD7D.taxon	materials_examined	Material examined. Holotype. ♀ JAPAN: Okayama Pref., Niimi City, Toyonaga Akouma, large and deep cave, 417 m, ~ 34.9864 ° N, 133.5844 ° E, 20. Apr. 2019, F. Ballarin & T. Yamasaki leg. (NSMT- 26851). Paratypes. 6 ♀, same locality and date as the holotype (3 ♀ NSMT- 26852, 3 ♀ MNHAH-B 6 - 000455). Other material examined. Porrhomma sp.: JAPAN, Gifu Pref.: 1 ♀, Gujo City, Hachiman-cho Iruma, Miyama shōnyūdō Cave (美Ɯ鍾ÂȒ), 570 m, 35.7497 ° N, 137.0250 ° E, 1. Aug. 2024, F. Ballarin & T. Nagai leg. (FBPC).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFCBE53BFF4AF8A431EAFD7D.taxon	etymology	Etymology. The specific name refers to Niimi city (Ế 見 ṁ), from where the new species was found.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFCBE53BFF4AF8A431EAFD7D.taxon	diagnosis	Diagnosis. Species closely related to other Japanese troglobitic Porrhomma species of the P. magnum group. Female of P. niimiensis sp. nov. can be separated from female of P. rakanum and by having the main sack of the spermatheca, coiled, headed internally and dorsally, folded toward the main body of the spermatheca and partially covering it when the vulva is observed dorsally and anteriorly (vs comma-like, headed antero-ventrally, not covering the (cf. Fig. 25 B, E, F vs Figs 24 B, 25 G, H). The new species can be separated from female of P. okhawai by the longer ascending part of the copulatory grooves, approximately of the same width of spermatheca (vs ~ ½ width of spermatheca) and by the presence of one dorsal spine on Fe I (vs. four dorsal spines on Fe I) (cf. Fig. 25 B, E, F vs Saito 1977: figs 1, 7 and Růžička 2018: fig. 43 E).	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFCBE53BFF4AF8A431EAFD7D.taxon	description	Description. Female (holotype). Habitus as in Fig. 25 C. Total length: 1.98, carapace 0.84 long, 0.64 wide. Carapace uniformly light brown-yellowish lacking any pattern. Cephalic area as in Fig 25 D; AME and PME almost completely missing, ALE and PLE strongly degenerated, reduced to whitish maculae. Eyes measurements: AME = 0.00; ALE = 0.01, PME = 0.00, PLE = 0.03. Clypeus 0.14 long. Chelicera brownish, labium, and sternum light brown-yellowish. Chelicera with three teeth on promargin, three denticles on retromargin. Legs uniformly light brown-yellowish. Legs measurements: I 4.76 (1.32, 0.24, 1.23, 1.17, 0.80), II 4.36 (1.22, 0.26, 1.12, 1.06, 0.70), III 3.39 (0.97, 0.22, 0.79, 0.83, 0.58), IV 4.37 (1.25, 0.24, 1.13, 1.09, 0.66). Fe I with one dorsal and one retrolateral spines. Fe II with one dorsal spine. Tibial spine formula: 1 - 1 - 1 - 1, TmI = ~ 0.28, TmIV absent. Opisthosoma uniformly light grey lacking any pattern Epigyne and vulva as in Fig 25 A, B, E, F. Epigyne aperture (EA) wide, oval; posterior median plate (PMP) rectangular. Copulatory openings (CO) sclerotized, at sides of epigyne aperture. Internal ducts visible through tegument by transparency. Copulatory grooves (CG) long, first ascending anteriorly then folding and descending posteriorly before reaching spermathecae. Ascending part of copulatory grooves (AP) transparent, ~ as long as spermatheca width. Spermatheca sclerotized, twisted; appendix of spermatheca (A) short and thick, headed laterally, covered by main sack of spermatheca when vulva is observed posteriorly. Main sack of spermatheca (MS) short and stocky, headed internally, folded toward the main body of the spermatheca (MB). Male: unknown. Size variation. Female (n = 5) Total length: 1.90 – 1.98, carapace 0.78 – 0.85 long, 0.61 – 0.66 wide.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
03B387D3FFCBE53BFF4AF8A431EAFD7D.taxon	distribution	Distribution and ecology. Porrhomma niimiensis sp. nov. is known exclusively from the type locality cave (Fig. 28). We observed several individuals among rocks on the floor and in crevices of walls in a humid area near a subterranean creek in the dark zone of the cave. Troglobitic species.	en	Ballarin, Francesco, Nagai, Toshimichi, Yamasaki, Takeshi, Eguchi, Katsuyuki (2026): New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae). Zootaxa 5828 (3): 401-449, DOI: 10.11646/zootaxa.5828.3.1, URL: https://doi.org/10.11646/zootaxa.5828.3.1
