Ischnothyreus binorbis, Edward & Harvey, 2014

Edward, Karen L. & Harvey, Mark S., 2014, Australian Goblin Spiders Of The Genus Ischnothyreus (Araneae, Oonopidae), Bulletin of the American Museum of Natural History 2014 (389), pp. 1-144 : 57-60

Ischnothyreus binorbis , new species Figures 29–30 , map 6

TYPES: AUSTRALIA: Queensland: Male holotype and female allotype from Lamb Range , 19 km SE Mareeba, 17.1 ° S, 145.5667 ° E, 1200 m (3 Dec 1988, G. Monteith, G. Thompson), deposited in QM (³ holotype: QM S38628, PBI _ OON 00022047 ; ♀ allotype: QM S38628, PBI _ OON 00025759 ) .

ETYMOLOGY: The specific epithet is derived from the Latin bi- (‘‘two’’) and orbis (‘‘circle’’) ( Brown, 1956), and refers to paired circular-shaped depressions in the epigynum area of the female.

DIAGNOSIS: This species can be easily identified by the small stub-shaped lateral process positioned medially on the prolateral aspect of the male palpal bulb, the complex embolic region that is split into a number of curved processes, and the lighter orangebrown coloration of the palpal bulb (figs. 29G–H, 30A, B, E). Females exhibit small, circular paired epigynal atriums either side of a very long convoluted duct (figs. 29I, 30F).

MALE (PBI_OON_00022047, figs. 29A–C, G–H, 30A–E). Total length 1.38. CEPHA- LOTHORAX: Carapace pale orange, broadly oval in dorsal view, pars cephalica slightly elevated in lateral view, anteriorly narrowed to 0.49 times its maximum width or less, anterolateral corners without extension or projections, surface of elevated portion of pars cephalica smooth, sides finely reticulate. Clypeus margin unmodified, curved downward in front view, low, ALE separated from edge of carapace by less than their radius; setae light. Eyes: ALE largest, ALE circular, PME oval, PLE oval; posterior eye row straight from above; ALE touching, ALE- PLE touching. Sternum longer than wide, pale orange, uniform; setae dark, evenly scattered. Chelicerae, endites, and labium dark red-brown, chelicerae pale. Chelicerae straight, anterior face unmodified; promargin with one larger denticle; fang shape normal, without prominent basal process; setae light. Labium elongated hexagon, not fused to sternum, anterior margin indented at middle, much more heavily sclerotized than sternum; with six or more setae on anterior margin. Endites anteromedian tip with one strong, toothlike projection, much more heavily sclerotized than sternum. ABDOMEN: Ovoid; dorsum soft portions white. Book lung covers elliptical. Dorsal scutum pale orange, covering more than 3/4 of abdomen, no soft tissue visible from above, middle surface smooth, sides smooth. Epigastric scutum small lateral sclerites present. Postepigastric scutum pale orange, covering about 3/4 of abdominal length. Dorsum, epigastric area, and postepigastric area setae dark. LEGS: Yellow, without color pattern; patella plus tibia I shorter than carapace. Leg spination: femora: I p0-1-1; II p0-1-0; tibiae: I, II p2-2-0; v2-2-0; metatarsi: I, II p1-1-0; v1- 1-0. GENITALIA: Palp proximal segments dark red-brown; embolus dark; femur shorter than trochanter; patella shorter than femur; cymbium dark red-brown; bulb orangebrown, 1 to 1.5 times as long as cymbium, stout; palpal bulb with small stub-shaped lateral process positioned medially on prolateral aspect; embolic region complex, split into number of stout and curved processes (fig. 30A, B).

FEMALE (PBI_OON 25759, figs. 29D–F, I, 30F). Total length 1.68. CEPHALOTHO- RAX: Carapace nonmarginal pars cephalica setae dark. Clypeus straight in front view. ABDOMEN: Dorsal scutum covering 1/2 to 3/4 of abdomen, between 1/4 and 1/2 abdomen width. Postepigastric scutum widely hexagonal, only around epigastric furrow. LEGS: Leg spination: femora: I p0-1-1; II p0- 1-0; tibiae: I, II p2-2-0; v2-2-0; metatarsi: I, II p1-1-0; v1-1-0. GENITALIA: Ventral view: epigynal atrium paired, small and circular, sclerotization heavier on anterior portion; convoluted duct very long, much thicker than apodemes (figs. 29I, 30F).

OTHER MATERIAL EXAMINED: AUS- TRALIA: Queensland: Lamb Range , 19 km SE Mareeba, 1200 m, 17.10000 ° S, 145.56670 ° E, Dec. 3, 1988 (G. Monteith, G. Thompson, QM S58039, PBI _OON 22167), 1 ♀ ; Lamb’s Head , 20 km SW Cairns, rainforest, leaf litter, 1200 m, 17.03333 ° S, 145.65000 ° E, Nov. 10, 1981 (G. Monteith, QM S78312, PBI _OON 20628), 1 ♀ ; Lambs Head , 10 km W Edmonton, 1200 m, 17.03333 ° S, 145.65000 ° E, Dec. 10, 1989, to Jan. 08, 1990 (G. Monteith, G. Thompson, H. Janetzki, QM S58166, PBI _OON 22084), 5 ³ ; Mount Haig , 1000 m, 17.09833 ° S, 145.60170 ° E, Feb. 25, 1997 (G. Monteith, QM S37497 , PBI _OON 21749), 2 ³, 3 ♀ .

DISTRIBUTION: This species is known only from the Lamb Uplands (LU) subregion of the Wet Tropics Bioregion, in northeastern Queensland (map 6).

Figures

Fig. 29. Ischnothyreus binorbis, sp. nov. Holotype male (PBI_OON 00022047): A. habitus, dorsal view; B. habitus, ventral view; C. habitus, lateral view; G. carapace, anterior view; H. sternum, ventral view. Allotype female (PBI_OON 00025759): D. habitus, dorsal view; E. habitus, ventral view; F. habitus, lateral view; I. epigynum, ventral view.

Fig. 30. Ischnothyreus binorbis, sp. nov. Holotype male (PBI_OON 00022047): A. left palp, prolateral view; B. left palp, retrolateral view; C. left chelicerae, anterior view; D. left chelicerae, posterior view; E. left palp, dorsal view. Allotype female (PBI_OON 00025759): F. epigynum, ventral view. Scale lines 5 0.1 mm.