Ischnothyreus digitus, 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 : 50-53

Ischnothyreus digitus , new species Figures 25–26 , map 3

TYPES: AUSTRALIA: Queensland: Male holotype from Clacherty Road, via Julatten, 16.5833 ° S, 145.3666 ° E (11 Oct. 1980, G. Monteith), deposited in QM ( S95930 , PBI_OON 00025965). Female allotype from Clacherty Road, Julatten, 16.57638 ° S, 145.36611 ° E (3 Apr. 2009, K. Edward and J. Waldock), deposited in QM ( S95931 , PBI_OON 00005676).

ETYMOLOGY: The specific epithet is of the Latin digitus , meaning ‘‘finger’’ ( Brown, 1956), and refers to the distinctive elongate digitiform process situated on the prolateral aspect of the male palpal bulb.

DIAGNOSIS: This species is unique and can be easily distinguished by the long digitiform lateral process positioned medially on the prolateral aspect of the male palpal bulb (fig. 26A, B). The embolic region of the male palp is not obtusely bent or tapered. Females of the species can be identified by the uniquely shaped epigynal atrium, which is an elongate Ù-shape. The convoluted duct winds only in the posterior section of epigynal atrium, with the anterior portion straight (figs. 25I, 26F).

MALE (PBI_OON 25965, figs. 25 A–C, G, H, 26 A–E). Total length 1.58. CEPHALO- THORAX: Carapace pale orange, broadly oval in dorsal view, pars cephalica strongly elevated in lateral view, anteriorly narrowed to between 0.5 and 0.75 times its maximum width, anterolateral corners without extension or projections, surface of elevated portion of pars cephalica finely reticulate, sides finely reticulate. Clypeus margin unmodified, curved downward in front view, high, ALE separated from edge of carapace by their radius or more. Eyes: ALE largest, ALE circular, PME circular, PLE oval; posterior eye row procurved from above; ALE touching, ALE-PLE touching. Sternum longer than wide, uniform, setae evenly scattered. Chelicerae straight, anterior face unmodified; promargin with two larger denticles; fang shape normal, without prominent basal process. Labium elongated hexagon, not fused to sternum, anterior margin indent- ed at middle, same as sternum in sclerotization; with six or more setae on anterior margin. Endites distally not excavated, anteromedian tip with one strong, toothlike projection, same as sternum in sclerotization. ABDOMEN: Ovoid; dorsum soft portions white. Book lung covers elliptical. Dorsal scutum pale orange, covering more than 3/4 of abdomen, more than 1/2 to most of abdomen width, middle surface smooth, sides smooth. LEGS: Without color pattern; patella plus tibia I shorter than carapace. Leg spination: femora: I p0-2-1; II p0-1-0; tibiae: I, II p2-2-0; v2-2-0; metatarsi: I, II p1-1-0; v1- 1-0; distal spine of femora I much smaller than medial spines. GENITALIA: Palp proximal segments dark red-brown; embolus dark; femur shorter than trochanter, without posteriorly rounded lateral dilation; patella shorter than femur; cymbium dark redbrown, without distal patch of setae; bulb dark red-brown, more than two times as long as cymbium, stout; palpal bulb with long digitiform lateral process positioned medially on prolateral aspect (fig. 26A, B), embolic region not obtusely bent or tapered.

FEMALE (PBI_OON 5676, figs. 25 D–F, I, 26F). Total length 1.62. CEPHALOTHO- RAX: Carapace yellow-brown, ovoid in dorsal view, pars cephalica slightly elevated in lateral view, anteriorly narrowed to 0.49 times its maximum width or less. Clypeus straight in front view, low, ALE separated from edge of carapace by less than their radius; setae dark. Sternum pale orange; setae dark. Chelicerae, endites, and labium pale orange; setae dark. ABDOMEN: Dorsum soft portions pale orange. Dorsal scutum yellow-brown, covering 1/2 to 3/4 of abdomen, between 1/4 and 1/2 abdomen width. Epigastric scutum small lateral sclerites present. Postepigastric scutum pale orange, widely hexagonal, only around epigastric furrow. Dorsum, epigastric area, and postepigastric area setae dark. LEGS: Pale orange. Leg spination: femora: I p0-2-1; II p0-1-0; tibiae: I, II p2-2-0; v2-2-0; metatarsi: I, II p1-1-0; v1-1-0; two very small spines on retrolateral side of femora I. GENITALIA: Ventral view: epigynal atrium elongate Ùshape, anterior portion with necklike indents, triangular process overhanging posterior portion; convoluted duct thicker than apodemes, only convoluted in posterior section of epigynal atrium, anterior portion straight (figs. 25I, 26F).

OTHER MATERIAL EXAMINED: AUS- TRALIA: Queensland: Clacherty Road, Julatten , rainforest, leaf litter, 16.57638 ° S, 145.36611 ° E, Apr. 3, 2009 (K. Edward and J. Waldock, QM S95932 , PBI _ OON 5560 ), 1 ♀ ; Clacherty Road, Julatten , rainforest, leaf litter, 16.57638 ° S, 145.36611 ° E, Apr. 3, 2009 (K. Edward and J. Waldock, QM S95933 , PBI _ OON 5677 ), 1 ♀ ; Clacherty Road, Julatten , rainforest, leaf litter, 16.57638 ° S, 145.36611 ° E, Apr. 3, 2009 (K. Edward and J. Waldock, QM S95934 , PBI _OON 26310), 1 ♀ ; Clacherty Road, via Julatten , rainforest, leaf litter, 16.5833 ° S, 145.3666 ° E, Oct. 11, 1980 (G. Monteith, QM S12968 ), 1 ³, 1 ♀ ; Mossman Gorge National Park , rainforest, 16.47167 ° S, 145.33330 ° E, July 22, 1992, to Nov. 27, 1992 (R. Raven, P. Lawless, E. Lawless, M. Shaw, QM S22644 , PBI _OON 21729), 1 ♀ ; Mossman Gorge National Park , rainforest, leaf litter, 16.47167S, 145.33330E, Oct. 20, 1980 (G. Monteith, QM S12955 , PBI _OON 25945), 1 ♀ ; Rex Lookout, via Mossman , rainforest, leaf litter, 16.50 ° S, 145.383 ° E, Oct. 13, 1980 (G. Monteith, QM S12964 , PBI _OON 25946), 1 ³ .

DISTRIBUTION: This species is known only from two northern subregions of the Wet Tropics Bioregion (CU and ML), in northeastern Queensland (map 3).

Figures

Fig. 25. Ischnothyreus digitus, sp. nov. Holotype male (PBI_OON 00025965): A. habitus, dorsal view; B. habitus, ventral view; C. habitus, lateral view; G. carapace, anterior view; H. sternum, ventral view. Allotype female (PBI_OON 00005676): D. habitus, dorsal view; E. habitus, ventral view; F. habitus, lateral view; I. epigynum, ventral view.

Fig. 26. Ischnothyreus digitus, sp. nov. Holotype male (PBI_OON 00025965): 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 00005676): F. epigynum, ventral view. Scale lines 5 0.1 mm.