Dysderoides Fage, 1946

Grismado, Cristian J., Deeleman, Christa, Piacentini, Luis N., Izquierdo, Matías A. & Ramírez, Martín J., 2014, Taxonomic Review Of The Goblin Spiders Of The Genus Dysderoides Fage And Their Himalayan Relatives Of The Genera Trilacuna Tong And Li And Himalayana, New Genus (Araneae: Oonopidae), Bulletin of the American Museum of Natural History 2014 (387), pp. 1-108 : 11-12

Dysderoides Fage

Dysderoides Fage, 1946: 382 (type species by original designation Dysderoides typhlos Fage, 1946 ).

DIAGNOSIS: This genus resembles Trilacuna and Himalayana by the chelicerae abruptly narrowed distally, the deeply incised labium (fig. 3A–C), and the genitalic morphology (females with an anteriorly elongate, solid sclerite, small posterior receptacle, and transverse sclerotized plates posterior to the epigastric furrow, as in fig. 14C, D; and males with paraembolic laminae with filiform projections and internal thin, tortuous tube, see figs. 14A, B); it differs from both genera by lacking eyes and having well-developed macrosetae on legs III and IV.

DESCRIPTION: Male: Cephalothorax: Carapace yellow-brown, without any pattern, broadly oval in dorsal view, pars cephalica slightly elevated in lateral view, anteriorly narrowed to 0.49 times its maximum width or less, with rounded posterolateral corners, posterolateral edge without pits, posterior margin not bulging below posterior rim, anterolateral corners without extension or projections, posterolateral surface without spikes, surface of elevated portion of pars cephalica smooth, sides smooth, thorax without depressions, fovea absent, without radiating rows of pits; lateral margin straight, smooth, without denticles; marginal setae probably present in most specimens, only the bases remain in preserved specimens. Clypeus margin unmodified, straight in front view, vertical in lateral view, median projection absent; setae light, needlelike. Chilum absent. Eyes absent (remnants still visible in D. synrang , fig. 13G). Sternum longer than wide, usually without radial furrows between coxae I–II, II–III, III–IV, uniform, not fused to carapace, median concavity absent, surface smooth, without pits, microsculpture absent, anterior margin unmodified, posterior margin usually not extending posteriorly of coxae IV, anterior corner unmodified, lateral margin without infracoxal grooves, distance between coxae approximately equal, precoxal triangles present, lateral margins unmodified, without posterior hump; setae sparse, dark, needlelike, evenly scattered, originating from surface, without hair tufts. Mouthparts: chelicerae straight, anterior face unmodified; without teeth on both promargin and retromargin; fangs without toothlike projections, directed medially, shape normal, without prominent basal process, tip unmodified (as in fig. 2D); setae light, needlelike, evenly scattered; paturon inner margin with pairs of enlarged setae, distal region abruptly narrowed, posterior surface unmodified, promargin unmodified. Labium triangular, anterior margin deeply incised (as in fig. 3C), same as sternum in sclerotization, not fused to sternum; with six or more setae on anterior margin, subdistal portion with unmodified setae. Endites distally not excavated, serrula present in single row (as in fig. 3H), anteromedian tip unmodified, posteromedian part unmodified, same as sternum in sclerotization. Abdomen: Ovoid, without long posterior extension, rounded posteriorly; dorsum soft portions usually white or pale whitish, without color pattern. Book lung covers large, elliptical, without setae, anterolateral edge unmodified. Posterior spiracles connected by groove. Scutopedicel region unmodified, scutum not extending far dorsal of pedicel, plumose hairs absent. Dorsal scutum covering almost whole dorsum, weakly sclerotized, without color pattern, middle surface smooth, sides smooth. Epigastric scutum weakly sclerotized, surrounding pedicel, not protruding. Postepigastric scutum weakly sclerotized, long, almost rectangular, covering nearly full length of abdomen length, anterior margin unmodified, without posteriorly directed lateral apodemes. Spinneret scutum present, incomplete ring. Dorsum setae light, needlelike. Epigastric area setae uniform, light, needlelike. Postepigastric area setae light. Spinneret scutum without fringe of setae. Legs: Pale, without color pattern; femur IV not thickened, same size as femora I–III, patella plus tibia I longer than carapace, tibia I unmodified, tibia IV ventral scopula absent, metatarsi III and IV weak, ventral scopula absent. Leg spines present, usually with four ventral pairs on leg I and two ventral pairs on leg II. Spines on tibiae and metatarsi of legs III–IV more variable, but always present and well developed, at least on tibia III and tibia and metatarsus IV. Tarsi I–IV without inferior claw (as in fig. 5E–I). Genitalia (only males of D. muang and D. kanoi are known): Epigastric region with sperm pore large, oval, situated at level of anterior spiracles, unmodified; furrow without Ω- shaped insertions. Palp normal size, not strongly sclerotized, right and left palps symmetrical, proximal segments yellow-brown; embolus light, prolateral excavation absent; trochanter normal size, unmodified; femur normal size, two or more times as long as trochanter, without posteriorly rounded lateral dilation, attaching to patella basally; patella shorter than femur, not enlarged, setae unmodified; cymbium yellow-brown, narrow in dorsal view, not fused with bulb, not extending beyond distal tip of bulb; bulb 1 to 1.5 times as long as cymbium, tapering apically, middle part with a tortuous and thin internal tube that ends at the embolic division; distal part with several laminae that bear filiform projections surrounding the embolus.

Female: As in male except as noted. Palp without claw; spines absent; tarsus unmodified. Abdomen: Dorsal scutum small, covering less than half of dorsum (figs. 12D, 13A), or absent (fig. 11A). Epigastric scutum without lateral joints. Postepigastric scutum short, only around epigastric furrow, not fused to epigastric scutum. Supraanal scutum absent. Postepigastric area setae needlelike. Colulus represented only by setae. Legs: Trichobothria (examined only in D. muang ) base rounded, aperture internal texture not gratelike, hood smooth (fig. 6A–G). Legs III and IV with long spines (figs. 4F–H, 12F–G). Tarsal organ (examined only in the female of D. muang ) in legs I–II with three sensilla, III, IV and palp with two sensilla (fig. 6H–K). Genitalia: Between the epigastric and postepigastric scuta there are one (figs. 7H, 9H, 11H) or two (fig. 14C–D) transverse ventral plates present, adjacent to a pair of short internal apodemes. In the small species from Thailand only one plate remains, presumably the posterior one, as it bears the apodemes. Internally, anterior sclerite narrow, apparently without lumen, with muscles attached (visible at least in the larger species), with or without a distal widening. Posterior receptacle rounded to ovoid. Copulatory opening detected only in D. kaew (fig. 9H), situated posteriorly to the epigastric furrow, suggesting an entelegyne condition (see below the detailed description of the genitalia of Trilacuna for comparison).

COMPOSITION: Six species, five of them here newly described.

DISTRIBUTION: Known from caves from Northern India and Thailand.

MISPLACED SPECIES: Telchius micans Simon, 1893 , five female syntypes from Venezuela, deposited in MNHN (examined); transferred to Dysderoides by Fage (1946: 384, fig. 1d–e), rejected here. Beyond the superficial resemblance in the carapace shape, T. micans syntypes have normally developed eyes, and lack the characteristic cheliceral and labial features of Dysderoides . They seem to belong to a still undescribed circum-Caribbean genus currently under study in the PBI project by Angelo Bolzern (personal commun.).

INTRAGENERIC RELATIONSHIPS: The two Indian species ( D. typhlos and D. synrang ) are larger and more heavily sclerotized than the Thai species ( D. muang , D. kanoi , D. kaew , and D. lawa ). The two former (known only by a single female each) have two transverse procurved ventral plates in the genitalia, while the remaining four seem to have lost the anterior one. Females of the Thai species lack the dorsal abdominal scutum, retained as a small oval shield in the Indian ones. Those differences suggest two groups of species, which could be tested after the discovery of males of the Indian species.