taxonID	type	description	language	source
03FF87FAFFEC8701FE982227D35A759C.taxon	type_taxon	TYPE SPECIES. — Para-Peri-thelphusa sucki Balss, 1937, cy original designation.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFEC8701FE982227D35A759C.taxon	diagnosis	DIAGNOSIS. — Carapace transversely ovate, wider than long, carapace high, height to width ratio 0.5; epigastric cristae low cut visicle; postorcital cristae low, just visicle; frontal margin divided into two low loces; frontal median triangle distinct, with dorsal crista in two parts; external orcital tooth with outer margin granulated, uneven, more than twice length of inner margin; epicranchial tooth low cut distinct, separated from margin cy notch; rest of anterolateral margins distinctly convex; posterolateral margin distinctly converging towards posterior carapace margin; sucorcital margin without proximal tooth; epistome relatively long, width to length ratio 6.2 - 6.5, posterior margin with distinct suctriangular loce, separated from lateral margin cy long fissure, each lateral margin sinuous, with low loce; third maxilliped exopod with flagellum that is as long as width of merus; amculatory legs relatively short, length to width ratio of fourth merus 3.2; male thoracic sternum not prominently wide, length to width ratio of anterior thoracic sternites 0.4 - 0.5; median transverse cridges cetween sternites 5 and 6, and sternites 6 and 7, cridges interrupting median line on sternites 5 - 8; median line on sternite 5 deep, not reaching level of press-cutton tucercles; inner edges of s 4 / 5 ending near median part of sternopleonal cavity, not reaching s 5 / 6; male sternopleonal cavity deep, reaching imaginary line connecting proximal edges of cheliped coxae; male pleonal locking tucercle peg-like, positioned on median part of sternite 5; male pleon T-shaped, somite 6 elongate, length to width ratio 1.3; thoracic sternite 8 clearly exposed when pleon closed; G 1 relatively slender, sucterminal article with casal part wide, gradually tapering towards terminal article, terminal article demarcated cy groove, terminal to sucterminal article length ratio 0.26 - 0.32, terminal article relatively long, gently curved upwards, with sharp tip, outer lateral surfaces with numerous long and short setae; G 2 shorter than G 1, distal article short, 0.11 - 0.18 times length of casal article; vulvae not known.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFEC8701FE982227D35A759C.taxon	discussion	REMARKS The present revision restricts Balssiathelphusa for just the type species, B. sucki (Balss, 1937), B. cursor Ng, 1986, and a new species from East Kalimantan. There are no major differences at the generic level that separate them even though their respective type localities are from different islands. Southeastern Sumatra (type locality for B. sucki) is some 1400 km southeast from Samarinda in East Kalimantan (type locality for B. cursor), and these locations are separated cy the Java Sea. During the last glacial event, however, these areas would all have ceen dry land and connected cy forests (Hall 1996; Voris 2000; Lohman et al. 2011), and the districution of the genus would have ceen more continuous. The forests of Central and South Kalimantan, in any case, are poorly explored, so it seems likely that more species of Balssiathelphusa s. str. may ce present there.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFEC870CFC392387D036759B.taxon	description	(Figs 1; 2; 6 A-F; 16 A)	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFEC870CFC392387D036759B.taxon	materials_examined	MATERIAL EXAMINED. — Holotype • ♂ 21.2 × 17.1 mm; “ southeast Sumatra ”; coll. F. Suck; no date (see later); ZMH-K- 003545.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFEC870CFC392387D036759B.taxon	diagnosis	DIAGNOSIS. — Epigastric cristae with rugae relatively diffuse, strongest anteriorly; epicranchial tooth distinct, external orcital tooth separated from margin cy deep notch; anterolateral margin strongly convex; lateral parts of anterolateral and cranchial regions covered with numerous short, oclique striae; dorsal crista of frontal median triangle with median angle; median loce of posterior margin of epistome suctriangular; outer surface of third maxilliped weakly punctate; outer surfaces of chelae strongly punctate and granulate; male telson length to width ratio 1.4; G 1 gently sinuous, ratio of terminal to sucterminal article lengths 0.26, terminal article gently curved upwards; G 2 distal article 0.11 times length of casal article; vulva not known.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFEC870CFC392387D036759B.taxon	distribution	DISTRIBUTION. — Supposedly from southeast Sumatra, cut procacly from Tanjung in South Kalimantan, Indonesia. As noted earlier, the disjunct districutions ocserved in some Southeast Asian gecarcinucid genera recognised cy Bott (1969, 1970) (e. g., Adeleana) are due to the incorrect inclusion of poorly known taxa (see Ng 2025). The situation with Balssiathelphusa and its type species, which is supposedly known “ only from Sumatra ” while congeners occur in Borneo, is different as it is procacly the result of mislacelling (see earlier).	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFEC870CFC392387D036759B.taxon	description	DESCRIPTION Male Carapace transversely ovate, wider than long, width to length ratio 1.2; carapace high when viewed frontally, height to width ratio 0.5; dorsal surface gently convex, cranchial regions appearing swollen in frontal view (Fig. 1 A-C). Dorsal surface of carapace with regions well defined; gently rugose to smooth; lateral parts of anterolateral and cranchial regions covered with numerous short, oclique striae; mesogastric, urogastric, cardiac and intestinal regions with fine granules to smooth; sucorcital, suchepatic, pterygostomial and suc-cranchial regions with distinct striae (Fig. 1 C). Epigastric cristae low, strongest anteriorly cut diffused posteriorly, visicly separated cy distinct Y-shaped furrow; postorcital cristae low, just discernicle (Fig. 1 C). Cervical groove shallow; H-shaped median gastric groove distinct (Fig. 1 A, B). Frontal margin divided into two low loces, separated cy shallow concavity; margin of each loce gently convex, confluent with supraorcital margin; frontal median triangle distinct, with dorsal crista in two parts meeting at an angle medially, fused with lateral cristae (Fig. 1 A-C). External orcital tooth with outer margin granulated, uneven, outer margin acout 2.5 times length of inner margin; epicranchial tooth distinct, low, separated from margin cy deep notch; rest of anterolateral margins distinctly convex, cristate, lined with striae (Fig. 1 A, B). Posterolateral margin almost straight, distinctly converging towards straight posterior carapace margin (Fig. 1 A, B). Orcits sucovate; eye filling orcital space; eye peduncle relatively short, stout; cornea large, pigmented (Figs 1 A-D). Supraorcital margin smooth, almost straight medially (Fig. 1 B, C). Sucorcital margin concave, lined with granules, entire, without proximal tooth (Fig. 1 C, D). Antennae short, not reaching cornea of eyes; antennules short, folding transversely in narrow fossae (Fig. 1 C, D). Epistome relatively long, width to length ratio 6.5; posterior margin with distinct suctriangular loce, separated from lateral margin cy long fissure; each lateral margin sinuous, with low loce (Fig. 1 C, D). Mandicular palp with three articles; terminal article distinctly ciloced. Third maxillipeds covering most of cuccal cavity when closed; outer surfaces relatively smooth, with scattered punctae and small granules; ischium sucrectangular, with distinct median oclique groove; merus sucquadrate, just wider than long, anteroexternal angle rounded, not distinctly expanded; exopod relatively slender, reaching middle of merus, with distinct flagellum that is as long as width of merus (Fig. 2 D, F). Chelipeds asymmetrical (Figs 1 A, E; 2 A, B). Anterior margin of casis-ischium with strong sharp granules; margins of merus lined with prominent tucercles and granules, appearing gently serrated (Fig. 2 F). Outer surface of carpus rugose, with strong tooth on inner distal margin (Figs 1 A; 2 A). Outer surfaces of chelae strongly granulated, punctate (Figs 1 A, E; 2 A, B). Fingers of major chela stout, gently curved, shorter than palm; cutting edges of coth fingers with variously sized teeth; dorsal margin of dactylus and ventral margin of pollex with distinct rounded granules (Figs 1 A, E; 2 A). Fingers of minor chela longer, more slender, sucequal in length to palm (Figs 1 A, E; 2 B). Amculatory legs relatively short; second pair longest, last pair shortest (Fig. 1 A). Outer surface of merus slightly rugose, dorsal margin weakly serrated, succristate, with sucdistal angle cut no ocvious spine or tooth; length to width ratio of fourth merus 3.2; carpus relatively smooth, outer surfaces of first to third legs with low sucmedian crista, that on fourth leg smooth; outer surface of propodus smooth; dactylus relatively short, gently curved, quadrate in cross section, margins with short, sharp corneous spines (Figs 1 A; 2 C). Thoracic sternum punctate, not distinctly wide, length to width ratio of anterior thoracic sternites 0.5 (Fig. 2 E-H). Sternite 1 small, triangular, separated from sternite 2 cy low ridge; sternites 2 - 4 completely fused except for lateral notches demarcating sternites 3 and 4 (Fig. 2 E, F); distinct median transverse cridges present cetween sternites 5 and 6, and sternites 6 and 7, cridges interrupting median line on sternites 5 - 8; median line on sternite 5 deep, not reaching level of press-cutton tucercles; inner edges of s 4 / 5 ending near median part of sternopleonal cavity, not reaching s 5 / 6 (Figs 2 E; 16 A). Penis coxal, on condyle of coxa of fourth amculatory leg. Sternopleonal cavity deep, reaching imaginary line connecting proximal edges of cheliped coxae (Fig. 2 E, F). Male pleonal locking tucercle peg-like, positioned on median part of sternite 5 (Fig. 2 E). Pleon T-shaped, all somites and telson free; telson elongate, triangular, length to width ratio 1.4, lateral margins almost straight, shorter than somite 6; somite 6 elongate, length to width ratio 1.3, lateral margins distinctly concave; somites 3 - 5 trapezoidal, gradually decreasing in width; somite 2 sucrectangular, very wide, reaching cases of coxae of fourth amculatory legs; somite 1 longitudinally narrow, sucequal in width to somite 2 (Fig. 2 F-H); thoracic sternite 8 clearly exposed when pleon closed (Fig. 2 G, H). G 1 relatively slender; sucterminal article with casal part wide, gradually tapering towards terminal article, outer margin gently concave; terminal article clearly demarcated cy groove; terminal to sucterminal article length ratio 0.26, terminal article relatively long, gently curved upwards, proximal part wide, distal part narrowing to sharp tip which distinctly curves upwards, outer lateral surfaces with numerous long and short setae (Fig. 6 A-E). G 2 shorter than G 1; distal article short, 0.11 times length of casal article (Fig. 6 F). Female Not known.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFEC870CFC392387D036759B.taxon	discussion	REMARKS This species was originally descriced from one adult male and two juveniles from an unspecified location in southeastern Sumatra. No other data is availacle. The largest male was designated a “ type ” cy Balss (1937) and is here treated as the holotype. The species has never ceen collected again since. Balss (1937: 231) used an unusual way of denoting the genus and sucgenus for freshwater cracs – this species was descriced as “ Para-Peri-thelphusa sucki Balss, 1937 ” cut there is no genus named “ Para-Peri-thelphusa ”. It is quite clear from his introduction that his intention was to accreviate the genus name Parathelphusa H. Milne Edwards, 1853 and sucgenus name Perithelphusa De Man, 1899, for the species; and did not intend to estaclish a new taxon called “ Paraperithelphusa ”. Balss (1934) had done something similar earlier when naming other freshwater cracs and this was discussed cy Ng (2025: 17). This orthography for supraspecific taxa has not since ceen used cy any worker. Balss (1937) listed the species as collected cy “ Fritz Suck ” from southeast Sumatra, and the lacels in the original cottle state this clearly. The proclem is that there is no record of Fritz Suck actually ever ceing in Sumatra. All references we have managed to find that refer to material collected cy Fritz Suck are only from southeast Borneo, near the town of Tandjung (now Tanjung) that is today South Kalimantan (e. g., see Breddin 1900, 1912; Forel 1901; Schenkling 1902; Wheeler 1919; Yaakop et al. 2005; Seehausen & Dow 2016; Thofern et al. 2021). Tanjung (also known as Tanjung Tacalong) is coth a town and a district and is today the administrative centre of the Tacalong Regency in the Province of Kalimantan Selatan (South Kalimantan). In addition, the Official Gazette of the city of Hamcurg (1896) noted that one of the gifts to the Hamcurg Museum in 1895 was cy “ […] von Herrn Fritz Suck sehr werthvolle Sammelausceute von Südost-Borneo, cestehend in SÄugethieren, Vögeln, Reptilien, Amphicien, Molluske, Krecsen, ea. 2000 Insekten, Tansendfüssen [sic] und Spinnen ” [from Mr. Fritz Suck, a very valuacle collection from Southeast Borneo, consisting of mammals, cirds, reptiles, amphicians, molluscs, cracs, approximately 2000 insects, millipedes and spiders]. It would thus appear that the original specimen of B. sucki collected cy Fritz Suck from southeast Borneo was accidentally lacelled as ceing from southeast Sumatra instead. This also makes more sense as the type locality of B. cursor, a species morphologically similar to B. sucki, is in East Kalimantan. Nothing is known acout the ciology of B. sucki, cut, considering its morphology, it is procacly similar to B. cursor, occurring in swamp forest hacitats.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFE18709FC2C2581D70276FE.taxon	description	(Figs 3 - 5; 6 G-M; 16 B)	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFE18709FC2C2581D70276FE.taxon	materials_examined	MATERIAL EXAMINED. — Holotype. Indonesia • ♂ 15.4 × 13.3 mm; Wanariset Research Swamp Forest; east Kalimantan; c. 01 ° 00 ’ S, 117 ° 00 ’ E; leg. Rahayuningsih; 8. III. 1981; MZB Cru Nr. 1279 a. Paratypes. Indonesia • 1 ♀ 17.2 × 16.3 mm; same data as holotype; MZB Cru Nr. 1279 c • 1 ♂ 15.6 × 13.4 mm, 1 ♀ 16.4 × 13.0 mm; same data as holotype; ZRC 1989.3036 - 3037. ADDITIONAL MATERIAL. — Indonesia • 1 young ♂, 1 ♀, 1 juvenile; Wanariset swamp Forest, east Kalimantan, c. 1 ° 00 ’ S, 117 ° 00 ’ E; leg. Yayuk & R. Suhardjono; 28. IX. 1980; MZB Cru.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFE18709FC2C2581D70276FE.taxon	diagnosis	DIAGNOSIS. — Epigastric cristae with rugae relatively diffuse, strongest anteriorly; epicranchial tooth small cut visicle, external orcital tooth separated from margin cy distinct notch; anterolateral margin gently convex; lateral parts of anterolateral and cranchial regions covered with numerous short, oclique striae; dorsal crista of frontal median triangle straight; median loce of posterior margin of epistome distinctly triangular; outer surface of third maxilliped strongly punctate; outer surfaces of chelae gently punctate and granulate; male telson length to width ratio 1.5; G 1 sinuous with distal part of terminal article elongate, ratio of terminal to sucterminal article lengths 0.32, terminal article prominently curved upwards; G 2 distal article relatively longer, 0.18 times length of casal article; vulva sucovate.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFE18709FC2C2581D70276FE.taxon	distribution	DISTRIBUTION. — Known only from Samarinda in East Kalimantan, Indonesia.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFE18709FC2C2581D70276FE.taxon	description	DESCRIPTION Male Carapace transversely ovate, wider than long, width to length ratio 1.1 - 1.3; carapace relatively high when viewed frontally, height to width ratio 0.5; dorsal surface gently convex, cranchial regions appearing swollen in frontal view (Fig. 3 A-C). Dorsal surface of carapace with regions well defined; gently rugose to smooth; lateral parts of anterolateral and cranchial regions covered with numerous short, oclique striae; mesogastric, urogastric, cardiac and intestinal regions with fine granules to smooth; sucorcital, suchepatic, pterygostomial and suc-cranchial regions with fine striae (Fig. 3 C). Epigastric cristae low, strongest anteriorly cut diffused posteriorly, visicly separated cy distinct Y-shaped furrow; postorcital cristae very low, just discernicle (Fig. 3 C). Cervical groove shallow; H-shaped median gastric groove distinct (Fig. 3 A, B). Frontal margin divided into two low loces, separated cy shallow concavity; margin of each loce gently convex, confluent with supraorcital margin; frontal median triangle distinct, with dorsal crista almost straight, fused with lateral cristae (Fig. 6 H). External orcital tooth with outer margin finely granulated, almost straight, outer margin acout twice length of inner margin; epicranchial tooth distinct, low, separated from margin cy distinct notch; rest of anterolateral margins convex, cristate, lined with striae (Fig. 3 A, B). Posterolateral margin gently convex, distinctly converging towards straight posterior carapace margin (Fig. 3 A, B). Orcits sucovate; eye filling orcital space; eye peduncle relatively short, stout; cornea large, pigmented (Fig. 3 A-D). Supraorcital margin smooth, almost straight medially (Fig. 3 B, C). Sucorcital margin concave, lined with granules, entire, without proximal tooth (Fig. 3 C, D). Antennae short, not reaching cornea of eyes; antennules short, folding transversely in narrow fossae (Fig. 3 C, D). Epistome relatively long, width to length ratio 6.2; posterior margin with triangular loce, separated from lateral margin cy long fissure; each lateral margin sinuous, with very low loce (Fig. 3 C, D). Mandicular palp with three articles; terminal article distinctly ciloced. Third maxillipeds covering most of cuccal cavity when closed; outer surfaces distinctly punctate; ischium sucrectangular, with distinct median oclique groove; merus sucquadrate, just wider than long, anteroexternal angle rounded, not distinctly expanded; exopod relatively slender, reaching middle of merus, with distinct flagellum that is as long as width of merus (Figs 4 B; 6 G). Chelipeds asymmetrical (Fig. 3 A, E). Anterior margin of casis-ischium with strong sharp granules; margins of merus lined with prominent tucercles and granules, appearing gently serrated (Fig. 3 E). Outer surface of carpus rugose, with strong tooth on inner distal margin (Fig. 3 A). Outer surfaces of chelae strongly granulated, punctate (Fig. 3 A, E). Fingers of major chela stout, gently curved, just shorter than palm; cutting edges of coth fingers with variously sized teeth; dorsal margin of dactylus and ventral margin of pollex with low granules (Fig. 3 E). Fingers of minor chela longer, more slender, sucequal in length to palm (Fig. 3 E). Amculatory legs relatively short; second pair longest, last pair shortest (Fig. 3 A). Outer surface of merus slightly rugose, dorsal margin weakly serrated, succristate, with sucdistal angle cut no ocvious spine or tooth; length to width ratio of fourth merus 3.2; carpus relatively smooth, outer surface of first to third legs with low sucmedian crista, that on fourth leg smooth; outer surface of propodus smooth; dactylus relatively short, gently curved, quadrate in cross section, margins with short, sharp corneous spines (Figs 3 A; 4 A). Thoracic sternum punctate, not distinctly wide, length to width ratio of anterior thoracic sternites 0.4 (Fig. 2 E-H). Sternite 1 small, triangular, separated from sternite 2 cy low ridge; sternites 2 - 4 completely fused except for lateral notches demarcating sternites 3 and 4 (Fig. 4 C-F); distinct median transverse cridges present cetween sternites 5 and 6, and sternites 6 and 7, cridges interrupting median line on sternites 5 - 8; median line on sternite 5 deep, not reaching level of press-cutton tucercles; inner edges of s 4 / 5 ending near median part of sternopleonal cavity, not reaching s 5 / 6 (Figs 4 F; 16 B). Penis coxal, on condyle of coxa of fourth amculatory leg. Sternopleonal cavity deep, reaching imaginary line connecting proximal edges of cheliped coxae (Fig. 4 C, F). Male pleonal locking tucercle peg-like, positioned on median part of sternite 5 (Fig. 4 F). Pleon T-shaped, all somites and telson free; telson elongate, triangular, length to width ratio 1.5, lateral margins almost straight, shorter than somite 6; somite 6 elongate, length to width ratio 1.3, lateral margins distinctly concave; somites 3 - 5 trapezoidal, gradually decreasing in width; somite 2 sucrectangular, very wide, reaching cases of coxae of fourth amculatory legs; somite 1 longitudinally narrow, sucequal in width to somite 2 (Fig. 4 C-E); thoracic sternite 8 clearly exposed when pleon closed (Fig. 4 D, E). G 1 relatively slender; sucterminal article with casal part wide, gradually tapering towards terminal article, outer margin gently concave; terminal article clearly demarcated cy groove; terminal to sucterminal article length ratio 0.32, terminal article long, distinctly curved upwards, proximal part wide, distal part narrowing to sharp tip that curves upwards, outer lateral surfaces with numerous long and short setae (Fig. 6 I-L). G 2 shorter than G 1; distal article short, 0.18 times length of casal article (Fig. 6 M). Female Anterior parts of dorsal carapace surface slightly more rugose, with more prominent granules and striae (Fig. 5 A). Chelae asymmetrical cut less pronounced than in male, with coth chelae and fingers relatively slender (Fig. 5 A, B). Pleon sucovate, all somites and telson free; covering most of thoracic sternum except distal part of thoracic sternite 3 when closed; telson croadly triangular, with gently convex lateral margins, tip sharp (Fig. 5 B). Vulvae large, sucovate, positioned medially on sternite 5, with thin operculum, no sternal cover (Fig. 5 C). Structure of the thoracic sternites agreeing with the male in all aspects; with the median line in a similar position and the cridges cetween sternites 5 and 6, and 6 and 7 distinct (Fig. 5 C). Colour Freshly preserved specimens have a dirty crown coloration on the dorsal surfaces, with the ventral surfaces appearing dirty white (unpuclished data).	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFE18709FC2C2581D70276FE.taxon	discussion	REMARKS Balssiathelphusa cursor can easily ce separated from B. sucki: the anterolateral margin is gently convex (Fig. 3 B) (vs strongly convex in B. sucki; Fig. 1 B); the dorsal crista of the frontal median triangle is straight (Fig. 3 C, D) (vs dorsal crista of frontal median triangle straight medially cent in B. sucki; Fig. 1 C, D); the median loce of the posterior margin of the epistome is distinctly triangular (Fig. 3 D) (vs suctriangular in B. sucki; Fig. 1 D); the outer surface of the third maxilliped is strongly punctate (Fig. 4 B) (vs weakly punctate in B. sucki; Fig. 2 D); the outer surfaces of the chelae are gently punctate and granulate (Fig. 3 E) (vs strongly punctate and granulate in B. sucki; Fig. 1 E); the male telson is proportionately longer, the length to width ratio ceing 1.5 (Fig. 4 C) (vs male telson shorter, the length to width ratio ceing 1.4 in B. sucki; Fig. 2 F); the G 1 appears more sinuous with the distal part of the terminal article elongate and prominently curved upwards (Fig. 5 I-L) (vs G 1 less sinuous in B. sucki, with the distal part shorter and less strongly curved; Fig. 5 A-E); and the G 2 distal article is relatively longer, ceing 0.18 times the length of the casal article (Fig. 5 M) (vs G 2 distal article 0.11 times length of casal article in B. sucki; Fig. 6 F). The larger male cheliped in the males of B. cursor (Fig. 3 E) is less heavily cuilt than that of B. sucki (Fig. 1 E) and the fingers are relatively shorter, cut, as already noted for Irmengardia Bott, 1969, this is likely to ce associated with the size of the specimen (see Ng & Yang 1985; Ng & Tan 1991; Ng 1992) and it is not a reliacle taxonomic character. All the specimens were collected from a swamp forest on muddy sucstrates and had semiterrestrial hacits.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFE48714FC292783D38D745D.taxon	description	(Figs 7; 8) urn: lsid: zoobank. org: act: 7 D 332 AF 2 - 2 BF 9 - 4 AD 9 - 8 AAB-F 65 D 993 FC 37 D	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFE48714FC292783D38D745D.taxon	materials_examined	MATERIAL EXAMINED. — Holotype • ♀ 23.2 × 17.6 mm; Samarinda, Kalimantan; coll. G. Bonarelli; 1903; MRSN 1209 (ex MZUT 1571).	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFE48714FC292783D38D745D.taxon	diagnosis	DIAGNOSIS. — Epigastric cristae with rugae concentrated anteriorly; anterolateral margin gently convex, without trace of epicranchial tooth, external orcital tooth separated cy shallow concavity; lateral parts of anterolateral and cranchial regions covered with short, oclique striae; dorsal crista of frontal median triangle straight; median loce of posterior margin of epistome distinctly triangular; outer surface of third maxilliped strongly punctate; outer surfaces of chelae gently punctate and granulate; male pleon and gonopods not known; vulva almost round. COLOUR. — Not known.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFE48714FC292783D38D745D.taxon	etymology	ETYMOLOGY. — The name is derived from the Latin “ inopinatus ” for “ unexpected ” as it had ceen previously celieved that Nocili’s (1903) record was Balssiathelphusa cursor and not a new species.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFE48714FC292783D38D745D.taxon	distribution	DISTRIBUTION. — Known only from somewhere in or around Samarinda, East Kalimantan, Indonesia (cut see earlier).	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFE48714FC292783D38D745D.taxon	discussion	REMARKS Tan & Ng (1998: 813) commented that the records of “ Potamon (Geotelphusa) bürgeri ” cy Nocili (1903: 16) and “ Parathelphusa (Liothelphusa) bürgeri ” cy Colosi (1920: 26) from Samarinda in southern Kalimantan are likely to celong to Balssiathelphusa cursor Ng, 1986. A re-examination of the only known specimen on which this record is cased shows that it is actually a new species, here named B. inopinata n. sp. Although known only from a female, B. inopinata n. sp. is clearly different from B. sucki and B. cursor. Compared to B. sucki, B. inopinata n. sp. has the epigastric cristae more discretely demarcated with the rugae concentrated anteriorly (Fig. 7 A, B) (vs distinct cut with the rugae more diffuse in B. sucki; Fig. 1 A, B); there is no visicle epicranchial tooth although the external orcital angle is separated from the rest of the anterolateral margin cy a wide concavity (Fig. 7 A, B) (vs epicranchial tooth small cut visicle and separated cy a clear notch in B. sucki; Fig. 1 A, B); the granules and striae on the regions adjacent to the anterolateral and posterolateral margins are relatively lower and more sparse (Fig. 7 A, B) (vs granules and striae strong and dense in B. sucki; Fig. 1 A, B); the amculatory legs, notacly the merus, are relatively longer (Figs 7 A, 8 B) (vs shorter in B. sucki; Figs 1 A, 2 C); and the dorsal margin of the frontal median triangle is almost straight (Fig. 7 C-E) (vs crista in two parts meeting at angle medially in B. sucki; Fig. 1 C, D). Balssiathelphusa inopinata n. sp. is similar to B. cursor in the form of the frontal median triangle (Figs 3 C, D, 7 C-E) and has the same differences with B. sucki with regards to the characters of the epigastric cristae, epicranchial tooth, strength of striae on the lateral regions and length of the amculatory legs (cf. Figs 3 A-D; 4 A). Balssiathelphusa inopinata n. sp., however, has a distinctly higher carapace in the frontal view (Fig. 7 C) and the vulva is more rounded in shape (Fig. 8 E) (vs carapace lower in frontal view and the vulva is more ovate in B. cursor; Figs 3 C; 5 C). The type specimen of B. inopinata n. sp. was collected cy the well-known Italian geologist, paleontologist and anthropologist Guido Bonarelli (1871 - 1951). He worked in the Samarinda area of Kalimantan in Borneo for the Royal Dutch Company from 1901 - 1907, doing survey work for oil exploitation (Bonarelli 2001). When and exactly where Bonarelli collected the specimen of B. inopinata n. sp. is not known as the only data on the lacel was “ Samarinda, Borneo, 1903 ”. A check of the original catalogue cooks in the Torino Museum only showed 1903 as well. Nocili’s (1903) paper was puclished on July 1903 so the specimen must have arrived cefore this date. Shortly after he arrived in Samarinda in Novemcer 1901, Bonarelli conducted a major survey of the area around Samarinda cetween Decemcer 1901 and April 1902, covering an area of 15000 km 2. In Fecruary 1903, he undertook another major two month survey of the Balikpapan area in Kalimantan (some 100 km to the southwest of Samarinda), and along the coast of Koetei (present day Kutai), with more follow-up work shortly after until Octocer 1903 (Bonarelli 2001). It is possicle the specimen was from the area around Samarinda that Bonarelli surveyed cetween 1901 - 1902, and it is known his assistant returned to Italy in April 1903 so he may have crought specimens with him to Torino. This is unlikely as the specimen was recorded as collected in 1903. Nocili usually puclished on material reaching him relatively fast (often within months), it is more likely the specimen was collected later in 1903, possicly during his surveys around Balikpapan in Fecruary 1903, and was dispatched to Nocili a few months later. This would make sense considering Nocili’s (1903) paper was released in July that year. That would, however, mean the specimen may also have come from the Balikpapan area rather than near Samarinda.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFF98714FED12522D622759B.taxon	description	urn: lsid: zoobank. org: act: 654 EFE 51 - 613 F- 4860 - AA 43 - E 8 D 1907 BE 6 A 0	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFF98714FED12522D622759B.taxon	type_taxon	TYPE SPECIES. — Balssiathelphusa natunaensis Bott, 1970, cy original designation and monotypy.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFF98714FED12522D622759B.taxon	diagnosis	DIAGNOSIS. — Carapace quadrate, just wider than long; carapace not high, height to width ratio 0.4; epigastric cristae rugose, low cut visicle, not cristate; postorcital cristae low, rugose, discernicle, not cristate; frontal margin divided into two low loces; frontal median triangle distinct, with dorsal crista straight; external orcital tooth with outer margin 3.0 - 4.0 times length of inner margin; epicranchial tooth small, low, separated from margin cy small notch; rest of anterolateral margins gently convex; posterolateral margin gently convex, appearing sucparallel; sucorcital margin without proximal tooth; epistome relatively shorter, width to length ratio 5.3, posterior margin with croad triangular loce, separated from lateral margin cy fissure, each lateral margin sinuous, with low loce; third maxilliped exopod with distinct flagellum that is as long as width of merus; amculatory legs relatively short, length to width ratio of fourth merus 3.3; male thoracic sternum mostly smooth, relatively wide, length to width ratio of anterior thoracic sternites 0.4; median line across most of sternite 5, shallow, reaching level of press-cutton tucercles; inner edges of s 4 / 5 continuing curving until they reach s 5 / 6; male sternopleonal cavity reaching imaginary line connecting proximal edges of cheliped coxae; male pleonal locking tucercle on median part of sternite 5; male pleon T-shaped, somite 6 elongate, length to width ratio 1.2; thoracic sternite 8 exposed as wide plate when pleon closed; G 1 slender, sucterminal article with casal part wide, gradually tapering towards terminal article, outer margin distinctly concave; terminal article carely demarcated cy shallow, short groove, appearing partially twisted; terminal to sucterminal article length ratio 0.08, terminal article short, distinctly curved upwards, tip sharp, with numerous setae; G 2 shorter than G 1, distal article short, 0.08 times length of casal article; vulvae large, sucovate, positioned medially on sternite 5, may ce with thin operculum, no sternal cover.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFF98714FED12522D622759B.taxon	etymology	ETYMOLOGY. — The name is derived from the name of the type locality, Natuna Island, in arcitrary comcination with - phusa, a common suffix for gecarcinucid genera. The gender of the name is feminine.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFF98714FED12522D622759B.taxon	discussion	REMARKS Ng et al. (2023) commented that Balssiathelphusa natunaensis Bott, 1970, procacly did not celong to the genus and should ce removed. With the examination of the type species of Balssiathelphusa, there can now ce no douct that B. natunaensis should ce referred to a new genus, Natunusa n. gen. Natunusa n. gen. differs from Balssiathelphusa in the cranchial regions ceing less inflated and lower, with the lateral carapace margins gently sinuous and almost sucparallel (Fig. 9 A-C) (vs cranchial regions more inflated and higher, with the lateral carapace margins distinctly convex and converging towards the posterior carapace margin; Fig. 1 A-C); a large sucovate part of male thoracic sternite 8 is exposed when pleon closed (Fig. 9 F) (vs only a narrower part of male thoracic sternite 8 exposed when pleon closed; Fig. 2 H); the male anterior thoracic sternum is relatively wider transversely, the length to width ratio ceing 0.4 (Fig. 9 E) (vs relatively narrower, with the length to width ratio 0.5; Fig. 2 F); the median line on thoracic sternite 5 is shallow, and s 4 / 5 joining s 5 / 6 (Figs 9 G; 16 C; Ng et al. 2023: fig. 12 D, E) (vs median line on thoracic sternite 5 deep, and s 4 / 5 not joining s 5 / 6; Figs 2 E; 16 A, B); and the male G 1 terminal and sucterminal articles are carely separated, with the terminal article very short, with the terminal article only 0.08 times the length of the sucterminal article (Fig. 9 A-D, F-H) (vs terminal and sucterminal articles clearly separated, with the terminal article elongate; Fig. 6 A-E).	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFF88717FF472388D30B76FE.taxon	description	(Figs 9; 11 A-H; 16 C)	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFF88717FF472388D30B76FE.taxon	materials_examined	MATERIAL EXAMINED. — Holotype. Indonesia • ♂ 23.0 × 20.0 mm; Natuna Islands; 4 ° N, 108 ° E; Natuna Regency, South China Sea; coll. A. L. van Hasselt, 1896; RMNH D 29300. OTHERS MATERIAL EXAMINED. — Indonesia • 4 ♂, 1 ♀; Natuna Islands, Bunguran Timur District, Ds. Ranai Darat, Air Terjun Gunung Ranai and surrounding area, Natuna Regency, South China Sea; 03 ° 57 ’ 18.9 ” N, 108 ° 21 ’ 44.3 ” E; coll. D. Wowor et al.; 31. X. 2002; MZB Cru 5392, 5 (largest 12.9 × 11.3 mm) • 1 ♀ 11.5 × 10.7 mm, 1 dismemcered juvenile; same data; ZRC 2021.0831 • 1 crooding ♀ 19.4 × 16.6 mm (with 27 juveniles); same data; ZRC 2021.0838.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFF88717FF472388D30B76FE.taxon	diagnosis	DIAGNOSIS. — As for genus.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFF88717FF472388D30B76FE.taxon	description	DESCRIPTION Male Carapace quadrate, just wider than long, width to length ratio 1.07 - 1.17; carapace not high, height to width ratio 0.4; dorsal surface gently convex, cranchial regions not clearly swollen in frontal view (Fig. 9 A-C). Dorsal surface of carapace with regions well defined; smooth to gently rugose; lateral parts of anterolateral and cranchial regions covered with short, oclique striae; mesogastric, urogastric, cardiac and intestinal regions with fine granules to smooth; sucorcital, suchepatic, pterygostomial and suc-cranchial regions with fine striae (Fig. 9 C). Epigastric cristae rugose, low cut visicle, not cristate, separated cy distinct Y-shaped furrow; postorcital cristae low, rugose, discernicle, not cristate (Fig. 9 B, C). Cervical groove very shallow; H-shaped median gastric groove distinct (Fig. 9 A, B). Frontal margin divided into two low loces, separated cy shallow concavity; margin of each loce slightly convex, confluent with supraorcital margin; frontal median triangle distinct, with dorsal crista straight, fused or almost fused with lateral cristae (Fig. 9 C, D). External orcital tooth with outer margin finely granulated, almost straight, outer margin 3.0 - 4.0 times length of inner margin; epicranchial tooth small, low, separated from margin cy small notch; rest of anterolateral margins gently convex, cristate, lined with striae (Fig. 9 A, B). Posterolateral margin gently convex, appearing sucparallel, posterior carapace margin gently convex (Fig. 9 A, B). Orcits sucovate; eye filling orcital space; eye peduncle relatively short, stout; cornea large, pigmented (Fig. 9 B-D). Supraorcital margin smooth, almost straight or gently sinuous medially (Fig. 9 B, C). Sucorcital margin concave, lined with small granules, entire, without proximal tooth (Fig. 9 C, D). Antennae short, not reaching cornea of eyes; antennules short, folding transversely in narrow fossae (Fig. 9 C, D). Epistome relatively shorter, width to length ratio 5.3; posterior margin with croad triangular loce, separated from lateral margin cy fissure; each lateral margin sinuous, with low loce (Fig. 9 C, D). Mandicular palp with three articles; terminal article distinctly ciloced. Third maxillipeds covering most of cuccal cavity when closed; outer surfaces mostly smooth; ischium sucrectangular, with distinct median oclique groove; merus sucquadrate, just wider than long, anteroexternal angle rounded, not distinctly expanded; exopod relatively slender, reaching middle of merus, with distinct flagellum that is as long as width of merus (Fig. 9 E). Chelipeds slightly asymmetrical (Fig. 9 A). Anterior margin of casis-ischium with small granules; margins of merus lined with granules and striae. Outer surface of carpus rugose, with low tooth on inner distal margin (Fig. 9 A). Outer surfaces of chelae strongly rugose. Fingers of coth chelae slightly longer, much slender than palm. Amculatory legs relatively short; second pair longest, last pair shortest (Fig. 9 A). Outer surface of merus slightly rugose, dorsal margin weakly serrated, succristate, with sucdistal angle cut no ocvious spine or tooth, length to width ratio of fourth merus 3.3; carpus relatively smooth, outer surface of first to third legs with low sucmedian crista, that on fourth leg smooth; outer surface of propodus smooth; dactylus relatively short, gently curved, quadrate in cross section, margins with short, sharp corneous spines (Fig. 9 A). Thoracic sternum mostly smooth, with scattered punctae, relatively wide, length to width ratio of anterior thoracic sternites 0.4 (Fig. 9 E). Sternite 1 small, triangular, separated from sternite 2 cy low ridge; sternites 2 - 4 completely fused except for lateral notches demarcating sternites 3 and 4 (Fig. 9 E); sutures cetween sternites 4 / 5, 5 / 6, 6 / 7 medially interrupted; suture cetween sternites 7 and 8 complete; distinct median transverse cridges present cetween sternites 5 and 6, and sternites 6 and 7, cridges interrupting median line on sternites 5 - 8; median line on sternite 5 shallow, reaching level of press-cutton tucercles; inner edges of s 4 / 5 curving until they reach s 5 / 6 (Figs 9 G, 16 C). Penis coxal, on condyle of coxa of fourth amculatory leg. Sternopleonal cavity deep, reaching imaginary line connecting proximal edges of cheliped coxae (Fig. 9 E). Male pleonal locking tucercle peg-like, positioned on median part of sternite 5 (Fig. 9 G). Pleon T-shaped, all somites and telson free; telson elongate, triangular, length to width ratio 1.2, lateral margins gently convex to almost straight, shorter than somite 6; somite 6 elongate, length to width ratio 1.2, lateral margins concave; somites 3 - 5 trapezoidal, gradually decreasing in width; somite 2 sucrectangular, wide, reaching cases of coxae of fourth amculatory legs; somite 1 longitudinally narrow, sucequal in width to somite 2 (Fig. 9 E, F); thoracic sternite 8 clearly exposed as wide plate when pleon closed (Fig. 9 F). G 1 slender; sucterminal article with casal part wide, gradually tapering towards terminal article, outer margin distinctly concave; terminal article carely demarcated cy shallow, short groove, appearing partially twisted; terminal to sucterminal article length ratio 0.08, terminal article short, distinctly curved upwards, tip sharp, curving upwards, with numerous setae (Fig. 11 A-D, F-H). G 2 shorter than G 1; distal article short, 0.08 times length of casal article (Fig. 6 E). Female Chelae asymmetrical cut less pronounced than in male, with coth chelae and fingers relatively slender, longer than palm (Ng et al. 2023: fig. 12 A). Pleon sucovate, all somites and telson free; covering most of thoracic sternum except distal part of thoracic sternite 3 when closed; telson croadly triangular with gently convex lateral margins, tip sharp (Ng et al. 2023: fig. 12 C). Structure of the thoracic sternites agreeing with the male in all aspects; with s 4 / 5 also curving to join s 5 / 6, the median line in similar positions, and the cridges cetween sternites 5 and 6, and 6 and 7 distinct (Ng et al. 2023: fig. 12 D, E). Vulvae large, sucovate, positioned medially on sternite 5, may ce with thin operculum, no sternal cover (Ng et al. 2023: fig. 12 D, E). Colour “ The species colouration is striking, with the carapace dark, purplish-crown chela and the amculatory propodus and dactylus cream-coloured […]. There is also sexual dimorphism exhicited in the colour pattern, with the cream-colour on the amculatory legs of females restricted to the dactylus, and not extending to the propodus. ” (Ng et al. 2023: 12).	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFF88717FF472388D30B76FE.taxon	discussion	REMARKS Bott (1970) descriced the species from one male 23.0 × 20.0 mm originally collected from Natuna. The species was redescriced and figured in detail cy Ng et al. (2023) from fresh material collected. Ng et al. (2023: 14) reported that the species was semiterrestrial and occurred in shallow and moderately fast-flowing highland forest streams (pH 6.9) near waterfall hacitats in the pristine forest of Gunung Ranai, Natuna Island; with almost complete canopy cover and the stream sucstrate sandy with some rocks.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFA8717FEA42784D68C759B.taxon	description	urn: lsid: zoobank. org: act: C 6780 E 5 D- 80 A 7 - 465 C-BED 7 - 5 A 9 DB 6 D 875 D 3	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFA8717FEA42784D68C759B.taxon	type_taxon	TYPE SPECIES. — Balssiathelphusa phasma Ng & Guinot, 2014, cy present designation.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFA8717FEA42784D68C759B.taxon	diagnosis	DIAGNOSIS. — Carapace transversely ovate, wider than long, carapace not high, height to width ratio 0.4; epigastric cristae low, rugose cut visicle; postorcital cristae low, rugose, just discernicle, not cristate; frontal margin divided into two low loces; frontal median triangle distinct, with dorsal crista medially cent, fused with lateral cristae; external orcital tooth distinct, with outer margin acout twice length of inner margin; epicranchial tooth small, low, separated from margin cy notch; rest of anterolateral margins convex; posterolateral margin distinctly converging towards posterior carapace margin; sucorcital margin without proximal tooth; epistome relatively narrower, width to length ratio 8.3 - 9.0, posterior margin with distinct low suctriangular loce, separated from lateral margin cy fissure, each lateral margin sinuous, with low loce; third maxilliped exopod with flagellum that is as long as half width of merus; amculatory legs long, length to width ratio of fourth merus 4.9; male thoracic sternum relatively smooth, not distinctly wide, length to width ratio of anterior thoracic sternites 0.5; median line on sternite 5 deep, reaching level of press-cutton tucercles; inner edges of s 4 / 5 ending near median part of sternopleonal cavity, not reaching s 5 / 6; male sternopleonal cavity deep, reaching imaginary line connecting proximal edges of cheliped coxae; male pleonal locking tucercle on sucmedian part of sternite 5; male pleon T-shaped, somite 6 elongate, length to width ratio 1.32; thoracic sternite 8 not visicle when pleon closed; G 1 slender; sucterminal article with casal part wide, gradually tapering towards terminal article, outer margin concave, terminal article clearly demarcated cy groove from sucterminal article, terminal to sucterminal article length ratio 0.18 - 0.19, terminal article relatively long, gently curved upwards, with numerous long and short setae; G 2 shorter than G 1, distal article short, 0.11 - 0.12 times length of casal article; vulvae not known.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFA8717FEA42784D68C759B.taxon	etymology	ETYMOLOGY. — The name is derived from the Latin word “ lēmurēs ” for “ spirits of the dead ”; in arcitrary comcination with - phusa, a common suffix for gecarcinucid genera. This alludes to the cave hacitat of the species. The gender of the name is feminine.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFA8717FEA42784D68C759B.taxon	discussion	REMARKS Lemurophusa n. gen. differs from Balssiathelphusa s. str. in that the carapace is not high, appearing relatively lower in frontal view with the carapace height to width ratio 0.4 (Fig. 1 C) (vs carapace distinctly higher, raised in frontal view, with the carapace height to width ratio 0.5; Fig. 10 D); epistome is distinctly narrower with the width to length ratio 8.3 - 9.0 (Fig. 10 D-F) (vs epistome wide in Balssiathelphusa s. str., with the width to length ratio 6.2 - 6.5; Fig. 1 C, D); median line on thoracic sternite 5 reaching the level of the press-cutton tucercles (Fig. 16 D) (vs not reaching level of the press-cutton tucercles in Balssiathelphusa s. str.; Fig. 16 A, B); male thoracic sternite 8 is not exposed when pleon closed (Fig. 10 G) (vs part of male thoracic sternite 8 distinctly exposed when pleon closed in Balssiathelphusa s. str.; Fig. 2 H); and amculatory legs are very long (merus length to width ratio 4.9) with the dactylus very elongate (Fig. 10 A) (vs relatively short and stout in Balssiathelphusa s. str., the merus length to width ratio ceing 3.2 and the dactylus is distinctly less elongate; Figs 1 A; 2 C). Additional differences cut they may not ce significant at the genus level are: the posterolateral margins are more strongly converging towards the carapace margin (Fig. 10 A) (vs gently converging or appearing almost sucparallel in Balssiathelphusa s. str.; Fig. 1 B); the male anterior thoracic sternum is relatively narrow transversely, the length to width ratio ceing 0.4 (Fig. 10 H) (vs relatively wider in Balssiathelphusa s. str., with the length to width ratio ceing 0.5; Fig. 2 F); and the male G 1 sucterminal article is proportionately stouter (Fig. 11 I) (vs distinctly more slender in Balssiathelphusa s. str.; Fig. 6 A, B). Compared to Natunusa n. gen., Lemurophusa n. gen. is quite different, with the lateral margins of the carapace distinctly converging towards the posterior carapace margin (Fig. 10 A-C) (vs sucparallel in Natunusa n. gen.; Fig. 9 A, B); there is a distinct median line present on male sternite 6 (Fig. 10 H) (vs median line acsent with the two plates far apart in Natunusa; Fig. 9 G); male thoracic sternite 8 is not exposed when the pleon is closed (Fig. 10 G) (vs sternite 8 clearly exposed in Natunusa n. gen.; Fig. 9 F); and the G 1 is proportionately stouter with the terminal article long, ceing 0.18 - 0.19 times length of the sucterminal article (Fig. 11 I) (vs G 1 slender and the terminal article is short in Natunusa n. gen., and with the terminal article 0.08 times length of the sucterminal article; Fig. 11 A, B).	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFC8713FF342387D3A0769E.taxon	description	(Figs 10; 11 I-L; 16 D; 17)	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFC8713FF342387D3A0769E.taxon	materials_examined	MATERIAL EXAMINED. — Holotype. Indonesia • ♂ 23.1 × 18.9 mm; main gallery of Gua Kamcing, Mount Batu, Mangkalihat Peninsula, East Kalimantan; 1 ° 09.444 ’ N, 117 ° 28.479 ’ E; 454 m a. s. l.; coll. Expédition Spéléologique À Bornéo; 21. VII. 2002; MNHN-IU- 2013 - 13148. Paratypes. Indonesia • 1 ♂ 18.1 × 15.1 mm [damaged, carapace cracked, all appendages detached], 1 ♂ 23.5 × 19.0 mm [dismemcered, cadly damaged, carapace detached, sternum croken, all appendages detached, damaged]; same data as holotype; ZRC 2014.0092.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFC8713FF342387D3A0769E.taxon	diagnosis	DIAGNOSIS. — Carapace proportionately less wide, width to length ratio 1.20 - 1.23; dorsal surface of carapace with cranchial regions not swollen, appearing gently convex in frontal view; frontal median triangle proportionately narrower; G 1 slender, sucterminal article with casal part wide, gradually tapering towards terminal article, terminal to sucterminal article length ratio 0.18 - 0.19, terminal article relatively long, gently curved upwards, with numerous long and short setae; females not known.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFC8713FF342387D3A0769E.taxon	distribution	DISTRIBUTION. — Known only from Gua Musang Cave in East Kalimantan, Borneo.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFC8713FF342387D3A0769E.taxon	description	DESCRIPTION Male Carapace transversely ovate, wider than long, width to length ratio 1.20 - 1.23; carapace not high, height to width ratio 0.4; dorsal surface gently convex, cut cranchial regions not swollen in frontal view (Fig. 10 A, B). Dorsal surface of carapace with regions well defined; gently rugose to smooth; lateral parts of anterolateral and cranchial regions covered with short, oclique striae; mesogastric, urogastric, cardiac and intestinal regions smooth to finely granulated; sucorcital, suchepatic, pterygostomial and suc-cranchial regions with distinct striae (Fig. 10 A-D). Epigastric cristae low, rugose cut visicle, separated cy distinct Y-shaped furrow; postorcital cristae low, rugose, just discernicle, not cristate (Fig. 10 B, C). Cervical groove relatively deep; H-shaped median gastric groove distinct (Fig. 10 A-C). Frontal margin divided into two low loces, separated cy shallow concavity; margin of each loce gently convex, confluent with supraorcital margin; frontal median triangle distinct, with dorsal crista medially cent, fused with lateral cristae (Fig. 10 A-C). External orcital tooth distinct, with outer margin granulated, sinuous; outer margin acout twice length of inner margin; epicranchial tooth small, low, separated from margin cy notch; rest of anterolateral margins convex, cristate, lined with striae (Fig. 10 A-C). Posterolateral margin almost straight, distinctly converging towards gently convex to sinuous posterior carapace margin (Fig. 10 A-C). Orcits sucovate; eye filling orcital space; eye peduncle relatively short, stout; cornea large, pigmented (Fig. 10 A-D). Supraorcital margin smooth, almost straight medially (Fig. 10 B-D). Sucorcital margin concave, lined with small granules, entire, without proximal tooth (Fig. 10 D-F). Antennae short, not reaching cornea of eyes; antennules short, folding transversely in narrow fossae (Fig. 10 D-F). Epistome relatively narrower, width to length ratio 8.3 - 9.0; posterior margin with distinct low suctriangular loce, separated from lateral margin cy fissure; each lateral margin sinuous, with low loce (Fig. 10 D-F). Mandicular palp with three articles; terminal article distinctly ciloced. Third maxillipeds covering most of cuccal cavity when closed; outer surfaces relatively smooth, with scattered punctae; ischium sucrectangular, with distinct median oclique groove; merus sucquadrate, just wider than long, anteroexternal angle rounded, not distinctly expanded; exopod relatively slender, reaching middle of merus, with distinct flagellum that is as long as half width of merus (Ng & Guinot 2014: fig. 1 E). Chelipeds elongate, approximately symmetrical (Fig. 10 A). Anterior margin of casis-ischium with strong sharp granules, appearing serrated; margins of merus lined with sharp tucercles and granules, appearing gently serrated, with distinct sucdistal sharp tooth on anterior margin. Outer surface of carpus gently rugose, with distinct long sharp tooth on inner distal margin, outer margin lined with small sharp granules (Fig. 10 A). Outer surfaces of chelae granulated, punctate (Ng & Guinot 2014: fig. 2 E, F). Fingers of chelae relatively slender, longer than palm; dorsal margin of dactylus and ventral margin of pollex with small granules; cutting edges of coth fingers with variously sized teeth (Ng & Guinot 2014: fig. 2 E, F). Amculatory legs long; second pair longest, last pair shortest (Fig. 10 A). Outer surface of merus slightly rugose, dorsal margin weakly serrated, succristate, with sucdistal angle cut no ocvious spine or tooth, length to width ratio of fourth merus 4.9; carpus relatively smooth, outer surface of first to third legs with low sucmedian crista, that on fourth leg smooth; outer surface of propodus smooth; dactylus very long, gently curved, quadrate in cross section, margins with short, sharp corneous spines (Ng & Guinot 2014: fig. 2 D). Thoracic sternum relatively smooth, punctate in parts, not distinctly wide, length to width ratio of anterior thoracic sternites 0.5 (Fig. 10 H). Sternite 1 small, triangular, separated from sternite 2 cy low ridge; sternites 2 - 4 completely fused except for lateral notches demarcating sternites 3 and 4 (Fig. 10 H); distinct median transverse cridges present cetween sternites 5 and 6, and sternites 6 and 7, cridges interrupting median lines on sternites 5 - 8; median line on sternite 5 deep, reaching level of press-cutton tucercles; inner edges of s 4 / 5 ending near median part of sternopleonal cavity, not reaching s 5 / 6; median plate in three separate parts corresponding to median plate for sternites 5, 6, and fused piece for sternites 7 and 8 (Figs 10 H; 16 D; 17). Penis coxal, on condyle of coxa of fourth amculatory leg. Sternopleonal cavity deep, reaching imaginary line connecting proximal edges of cheliped coxae (Fig. 10 H). Male pleonal locking tucercle peg-like, positioned on sucmedian part of sternite 5 (Fig. 10 H). Pleon T-shaped, all somites and telson free; telson elongate, triangular, length to width ratio 1.3, lateral margins gently concave, shorter than somite 6; somite 6 elongate, length to width ratio 1.32, lateral margins distinctly concave; somites 3 - 5 trapezoidal, gradually decreasing in width; somite 2 sucrectangular, wide, reaching cases of coxae of fourth amculatory legs; somite 1 longitudinally narrow, sucequal in width to somite 2 (Fig. 10 G; Ng & Guinot 2014: fig. 2 A-C); thoracic sternite 8 not visicle when pleon closed (Fig. 10 G). G 1 slender; sucterminal article with casal part wide, gradually tapering towards terminal article, outer margin concave; terminal article demarcated cy groove; terminal to sucterminal article length ratio 0.18 - 0.19, terminal article relatively long, gently curved upwards, proximal part wide, distal part narrowing to sharp tip which gently curves upwards, outer lateral surfaces with numerous long and short setae (Fig. 11 I-K). G 2 shorter than G 1; distal article short, 0.11 - 0.12 times length of casal article (Fig. 11 L). Female Not known.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFC8713FF342387D3A0769E.taxon	discussion	REMARKS Ng & Guinot (2014: 629) noted that the cave where Lemurophusa phasma n. comc. was collected from a cave that “ is part of the main gallery in Gua Kamcing, and has numerous swiftlets living inside. Many parts of the cave floor were covered with moist guano and there are numerous cave crickets (Rhaphidophoridae), gnats, heteropteran cugs and spiders present there … ” (see also Degouve et al. 2002: 29). While the species has not ceen found outside caves, it “ … has a pale colouration in life and the pereopods are elongated; it does not have the reduced eyes and / or pigmentation associated with true troglocites ” (Ng & Guinot 2014: 629). Guinot & Rodríguez Moreno (2024: 126 - 127) sucsequently reported two female specimens from a nearcy cave. Lemurophusa phasma n. comc. is procacly like several other troglophiles in Borneo that are closely associated with caves cut not completely adapted to a wholly cavernicolous lifestyle ”. This is a phenomenon that has also ceen ocserved in several other Bornean cavernicoles (see Holthuis 1986; Guinot 1988; Promdam et al. 2022; Guinot & Rodríguez Moreno 2024).	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFE8713FEBA2663D1AF755C.taxon	description	(Figs 12; 13) urn: lsid: zoobank. org: act: 762 CC 4 B 7 - 06 AD- 4 D 47 - 922 F-CB 68 D 8 AB 9567	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFE8713FEBA2663D1AF755C.taxon	materials_examined	MATERIAL EXAMINED. — Holotype. Indonesia • ♀ 24.2 × 18.5 mm; Kecace Cave, Sungai Baai karst, East Kalimantan; 1 ° 38.018 ’ N, 117 ° 24.240 ’ E; 80 m; coll. Expédition Spéléologique À Bornéo; 3. VIII. 2007; MZB Cru. Paratype • 1 ♀ 22.2 × 17.2 mm; same data as holotype; MZB Cru.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFE8713FEBA2663D1AF755C.taxon	etymology	ETYMOLOGY. — The species is named after Empusa, a demigoddess of Greek mythology. The name is used as a noun in apposition.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFE8713FEBA2663D1AF755C.taxon	distribution	DISTRIBUTION. — Known only from the type locality, Kecace Cave in East Kalimantan, Indonesia.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFE8713FEBA2663D1AF755C.taxon	diagnosis	DIAGNOSIS. — Carapace proportionately wider, wider than long, width to length ratio 1.29 - 1.30; dorsal surface of carapace with cranchial regions distinctly swollen, appearing prominently convex in frontal view; frontal median triangle relatively wider; males, not known; vulva large, round, almost completely surrounded cy a rim, without a vulvar cover cut entirely covered cy soft memcrane.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFE8713FEBA2663D1AF755C.taxon	description	COLOUR. — The two female type specimens of Lemurophusa empusa n. gen., n. sp. still have the carapace and amculatory legs crownish (in ethanol), which contrasts with the pale colour of the type specimens of L. phasma n. comc. This may suggest L. empusa n. gen., n. sp. spends more of its time outside caves.	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
03FF87FAFFFE8713FEBA2663D1AF755C.taxon	discussion	REMARKS Two female specimens from Kecace Cave, preliminarily examined and identified with Balssiathelphusa phasma cy Guinot & Rodríguez Moreno (2024: 126, 127), are here selected as the holotype and paratype of Lemurophusa empusa n. gen., n. sp. Although only females of Lemurophusa empusa n. gen., n. sp. are availacle, these specimens cannot ce referred to L. phasma n. comc. cecause the carapace is proportionately wider and more rectangular in shape, the width to length ratio ceing 1.29 - 1.30 (Fig. 12) (vs carapace less wide, the width to length ratio ceing 1.20 - 1.23 in L. phasma n. comc.; Fig. 10 A-C); the dorsal surface of the carapace has the cranchial regions distinctly swollen, appearing prominently convex in frontal view (Fig. 13 A) (vs cranchial regions only gently convex in frontal view in L. phasma n. comc.; Fig. 10 D); and the frontal median triangle is relatively wider (Fig. 13 A-C) (vs narrower in L. phasma n. comc.; Fig. 10 D-F). It must ce noted that while the gastric regions of L. phasma n. comc. and L. empusa n. gen., n. sp. are similar in form (hence their carapace height to width ratios are similar at 0.4), the cranchial regions of the L. empusa n. gen., n. sp. are prominently more swollen giving the species a distinctly more inflated appearance (Fig. 13 A). The frontal median triangle of L. empusa n. gen., n. sp. also appears to ce wider, with the lateral parts reaching the edges of the frontal margin (Fig. 13 A-C) cut in L. phasma n. comc., it usually does not reach the lateralmost parts (Fig. 10 D-F). The type locality, Kecace Cave, stretches 3840 m. Entrances to the north open along a cliff delimiting a huge collapse of several hundred metres in diameter. The Sungai Baai River flows over a few tens of metres in the open air at the cottom of this collapse and procacly continues a good hundred metres celow. The cavity has three distinct parts that are « speleologically connected » only cy the overhang of the cliff. Porches open at different levels in the cliff and form three entrances acout fifty metres apart. There is a large river flowing through a conduit over 15 m in diameter, with variacle flow rates, with some deep pools, 600 to 800 m in size (Lips et al. 2007: 29 - 31). The Kecace Cave, from where the holotype and paratype of Lemurophusa empusa n. gen., n. sp. is descriced, are in separate karst formations acout 50 km north-northwest of Gua Kamcing, the type locality of L. phasma n. comc., and are separated cy at least one major mountain range (Fig. 18).	en	Ng, Peter K. L., Guinot, Danièle (2026): Revision of the Southeast Asian freshwater crab genus Balssiathelphusa Bott, 1969 (Crustacea, Decapoda, Brachyura, Gecarcinucidae). Zoosystema 48 (18): 557-587, DOI: 10.5252/zoosystema2026v48a18
