Ischnothyreus tadetu sp. nov.

(Figures 2, 3)

Type material: Holotype: Male (IZCAS AR 19390), Laos, Champasak Province, Tad Etu, Unnamed Waterfall near Holiday Village, 15 º 11.639 'N, 106 º06.222'E, elevation 909 meters, November 19, 2012, leg. S. Li.

Etymology: The specific name is a noun in apposition taken from the type locality.

Diagnosis: The new species is similar to I. florifer Kranz-Baltensperger, 2011, but can be distinguished by the reduced dorsal scutum, the slightly sclerotized process at base of fangs and by the tip of the male palpal bulb.

Description: Male (holotype). Body length 1.69; carapace 0.92 length, 0.64 width; abdomen 0.89 length, 0.46 width. Habitus as in Figs 2 A–C. Carapace: orange-brown, with brown egg-shaped patches behind eyes, broadly oval in dorsal view, pars cephalica strongly elevated in lateral view, surface and sides strongly reticulate (Figs 2 D, E). Eyes: six, well developed, ALE largest, PME smallest; posterior eye row straight from above, procurved from front. Mouthparts (Fig. 2 F): chelicerae slightly divergent, with slightly sclerotized process at base of fangs (ssp in Fig. 3 D); fang groove with many small denticles (Figs 2 G, 3 D). Anterior margin of labium indented at middle. Anteromedian tip of endites with one strong, tooth-like projection (Fig. 2 C). Abdomen: scutum extending far dorsal of pedicel. Dorsal scutum covering about 2 / 3 of abdomen, about 3 / 4 of abdomen width, fused to epigastric scutum. Epigastric and postepigastric scutum well sclerotized, pale orange, fused. Leg formula: femur I with 2 prolateral and 1 small retrolateral spine, tibia I with 4 pairs, metatarsus I with 2 pairs of long ventral spines. Leg II spination is similar to leg I except femur with only 1 prolateral spine. Legs III and IV spineless. Genitalia: Sperm pore situated at level of anterior spiracles. Palp strongly sclerotized, trochanter with ventral projection; femur normal size; patella about as long as femur, not enlarged; cymbium not fused with bulb; bulb with one small ventral protuberance (vpr), at the distal end with a membranous outgrowth (ogr) (Figs 2 H–J, 3 A–C). Female: Unknown.

Distribution: Known only from the type locality.