Misgolas gracilis (Rainbow & Pulleine, 1918)

Wishart, Graham, 2006, Trapdoor Spiders of the Genus Misgolas (Mygalomorphae: Idiopidae) in the Sydney Region, Australia, With Notes on Synonymies Attributed to M. rapax, Records of the Australian Museum 58 (1), pp. 1-18 : 7-8

Misgolas gracilis (Rainbow & Pulleine, 1918)

Figs. 3A–I , 12A–B

Arbanitis gracilis Rainbow & Pulleine, 1918:110 , pl. 22, figs. 57–58.

Arbanitis villosus Rainbow, 1920, p. 77 –85, new synonym.

Arbanitis bradleyi Rainbow, 1920, p. 77 –85, new synonym.

Dyarcyops gracilis .– Main, 1977:71 (from Arbanitis ).

Misgolas gracilis .– Main, 1985b:24 (from Dyarcyops ).

Material examined. HOLOTYPE ♀, AM KS6262 , The Domain, Sydney (33°52'S 151°13'E), R.H. Pulleine.

Other material. Males: AM KS2170 , Randwick (33°55'S 151°15'E), 19 Dec. 1978, N. Coroneds ; AM KS3044 , Mudgee (32°36'S 149°35'E), 31 May 1979, Mudgee Pastures Protection Board ; AM KS6246 , Annandale (33°52'S 151°10'E), 14 Dec. 1980 ; AM KS8511 , Kendall (31°38'S 152°42'E), 15 Dec. 1981, C. Dick ; AM KS8813 , Tamworth (31°05'S 150°56'E), 15 Dec. 1981 ; AM KS10804 , Berowra Waters (33°35'S 151°07'E), 15 Mar. 1983 ; AM KS18393 , Blakehurst (33°59'S 151°06'E), 6 Jan. 1988 ; AM KS21512 , Heathcote (34°05'S 151°01'E), 28 Feb. 1989 ; AM KS22785 , Harbord (33°46'S 151°17'E), 9 Dec. 1989 ; AM KS22910 , Narrabeen (33°43'S 151°18'E), 24 Apr. 1929, E. Mitchell ; AM KS30221 , Tarago (35°04'S 149°39'E), 15 Feb. 1990, E. Gibson ; AM KS34720 , Glebe (33°53'S 151°11'E), 28 Jan. 1993 ; AM KS35042 , Potts Point (33°51'S 151°13'E), 20 Mar. 1993, Scott Barnes ; AM KS36577 , Bundeena (34°05'S 151°09'E), 18 Dec. 1973 ; AM KS38530 , Windsor (33°37'S 150°49'E), 11 Oct. 1929 ; AM KS50061 , Jamberoo (34°39'S 150°44'E), 15 Dec. 1995, L. Mitchell-Smith ; AM KS69954 , Bateau Bay (33°22'S 151°29'E), 20 Mar. 1999, L. Abra ; AM KS86211 , Symes Bay (32°21'S 152°30'E), 1 Mar. 2002, G. McKay. Females : AM KS7856 , Warrumbungle National Park (31°13'S 149°05'E), 1 Feb. 1969, M. Gray ; AM KS44339 , Yowie Bay (34°00'S 151°06'E), 23 Nov. 1994, Milton Way ; AM KS49338 , Towler’s Bay (33°37'S 151°19'E), 6 Feb. 1997 , GW; AM KS69955 , Pott’s Point (33°51'S 151°13'E) , T. Leslie.

Diagnosis. Medium to large dark brown spiders, eye group as narrow or narrower in front than behind; rd surface of metatarsi IV with a file of 1–4 long black spines ( Fig. 3F ). Venter pattern usually as figured ( Fig. 3D ), occasionally variable ( Fig. 3E,G or black). In female: Carapace length c. 8–13.2. In male: Carapace length c. 5–10.2; embolus of bulb and rl embolic flange as figured ( Fig. 3B,C ). Conformation of palp as figured ( Fig. 3A ). TEM exiguous, pl surface chitinized and bearing strong TET.

Remarks. The female holotype of this species was described from a specimen collected from The Domain, parkland on the southern shore of Sydney Harbour near the central business district. Three female paratypes are lost ( Main, 1985b). The holotype, preserved in alcohol, is a small female specimen, epigynum only moderately sclerotized. It is in poor condition, carapace damaged, abdomen detached, most limbs fractured and some segments missing. Markings on venter, described nature of burrow lid and precise locality where found allowed identification. No other Misgolas specimens are known from the type locality. An adult male collected from Potts Point, neighbouring the type locality of M. gracilis , is taken to be conspecific and is that described here.

Description of maleAM KS35042 ( Fig. 3A–E ). Size. Carapace length 8.82, width 6.37. Abdomen length 8.72, width 5.68. Colour. Carapace and limbs brown concolourous, dark brown smudges on limbs absent. Abdomen dorsum dark brown with distinct pale bands in bilateral series of eight. Venter pale with dark brown markings concentrated marginally to and between ental edges of posterior book lungs and others forming a broken transverse mid-line. Carapace. Edge fringed with long black bristles which encroach onto posterior half of post foveal surface. Sparse cover of pale hairs and weak black bristles; hairs extend onto limbs. Group of c. 10 bristles on clypeus. Weakly chitinized area with 3 setae extends onto pleuron membrane below clypeus. Fovea width 1.19, slightly recurved. Eyes. Raised on a mound; anterior width 1.31, posterior width 1.38, length 0.92, width/length ratio 1.50. Line joining posterior edge ofALE transects anterior 1 ⁄ 3 ofAME. Posterior row straight in front, recurved behind. Chelicerae. Rastellum 6(5) spines on antero-ental edge. Intercheliceral tumescence present. Fang groove with 7(7) promarginal teeth and 8(8) smaller retromarginal/intermediate row teeth.Weak serrated fang keel on pl edge. Labium. Bulbous. Length 0.84, width 1.07. Labiosternal suture divided. Maxillae. Cuspules c. 33(34) antero-ental stick-like, none surmounted by fine hair. Sternum. Length 5.16, width 3.07 appearing elongate. First and second pair sigilla round, submarginal; third pair oval, c. one diameter from margin. Legs. Tibia I with apical bifid apophysis; distal process with 2(2) short pointed spines, proximal process with 4(3) longer pointed spines.

Palp I II III IV Femur 5.03 7.94 7.35 6.26 8.53 Patella 2.46 4.12 3.78 3.25 4.11 Tibia 4.11 5.89 5.34 4.42 7.74 Metatarsus — 6.32 5.84 5.83 8.42 Tarsus 2.03 3.25 3.19 3.13 3.56 Total 13.63 27.52 25.50 22.89 32.36

Palp ( Fig. 3A ). Cymbium with c. 46 long strong anteriorly inclined, almost prostrate, spines widespread on distal 1 ⁄ 3 of d surface. RTA covered with d and rd short spines which continue along rl and rv edge of tibial excavation; DTA not hooked, covered with pointed short strong spines. TEM exiguous, with 3 hairs, pl surface chitinized and bearing strong TET. Bulb ( Fig. 3B,C ). Embolic rl flange thick, opaque, narrow, with one prominent fold, c. 4 small corrugations, twists under, around and along embolus terminating as a subdistal d mound. Scopula . Complete on all tarsi, dense on tarsi I and II, weak on III and IV; incomplete and sparse on all metatarsi. Trichobothria. Palp: tarsi 11, tibia pd6 rd6. Leg I: tarsi 12, metatarsi 16, tibia pd8 rd7. Leg II: tarsi 12, metatarsi 16, tibia pd7 rd7. Leg III: tarsi 12, metatarsi 13, tibia pd7 rd7. Leg IV: tarsi 12, metatarsi 17, tibia pd8 rd8. Leg spination. Leg I: metatarsi v012; tibia v0112, pd010. Leg II: tarsi rl row 7 small black spines; metatarsi rv0111113, pv011, pd000010; tibia v0113; pd01110. Leg III: tarsi v24 scattered; metatarsi pv6, rv8, d002220; tibia v0114, pl00110, rl00110; patella pd4. Leg IV: tarsi v17 strong scattered spines; metatarsi v8 strong spines, rd010; tibia v012. Abdomen. Dorsum with cover of fine bristles with underlying cover of fine hairs extending over venter.

Taxonomic note. Of 361 male specimens examined 31 (7.6%) bore no distal bifid tibial apophysis on leg I or else the apophysis was greatly reduced. The spiders were all of small size but not all small specimens were affected. These neotenic appearing forms were collected from widespread localities.The aberration has not been observed in other Misgolas species.

Distribution and natural history ( Fig. 12A,B ). This spider is the most widespread of any known Misgolas species found in NSW, ranging from Kendall and Tamworth in the north, west to the Warrumbungle Range, south to Mudgee and Tarago and thence east to Jamberoo ( Fig. 12A,B ). This distribution encompasses a variety of environments.

Collection dates of 361 male specimens held by AM indicate males wander throughout the year .

Burrow structure is given by Jordan (2001): Soil and silk burrow, door flap-like and fragile, semi-circular in shape, flattened on hinge side and silk lined below; a mature female burrow door measured c. 2 thick, 31 wide and 21 at right angles to hinge; thick silk around entrance rim; base of burrow enlarged and bulbous. This description concurs with burrow from which specimen AM KS49338 was excavated. Jordan (2001) noted M. gracilis hunted at entrance, door resting on caput. Tarsi of palps, legs I and II rest on rim visible beyond edge of door. Main (1976) records microhabitat preference and syntopic association with another Misgolas species.

Figures

Fig. 3. Misgolas gracilis. (A–D) Ƌ, AM KS22910. (A), right palp retrolateral. (B,C), right bulb: (B), dorsal; (C), prolateral. (D), venter. (E) Ƌ, AM KS34720, venter. (F,G) ♀, AM KS44339; (F), tarsus and metatarsus IV retrodorsal; (G), venter. (H,I) Ƌ, AM KS86211; (H), ventral aspect, palpal tibia excavation; (I), tibial excavation texture.

Fig. 12. Species distribution of Misgolas species in the Sydney region (eastern Australia) based on material examined. Key to symbols for maps (A) and (B): O Misgolas gracilis; A M. melancholicus; Z M. villosus. Map (C): • M. beni; Z M. cliffi; Δ M. lynabra; M. maculosus; O M. michaeli; * M. rodi; A M. trangi; * M. wayorum.