Zoma dibaiyin Miller, Griswold & Yin, sp. n.

urn:lsid:zoobank.org:act: C485899B-AB91-4989-9030-FC121273311D

Figs 10, 11 A-B, 13 A-D, 94

Material Examined. Holotype: CHINA: Yunnan; Fugong Co., Pee He, 40 km S Shangpa, SW of R., 26.54323°N, 98.89837°E, 1153 m, 23 August 2005, sifting bamboo litter at cliff base, P. Paquin, PP-4905 (CASENT 9029331, HNU), 1 ♀.

Paratypes: [same data as holotype] (CASENT 9020480, CAS), 1 ♁, 1 ♀; [same data as holotype] (CASENT 9020482, CAS), 1 ♀; [same data as holotype] (CASENT 9020481, HNU), 1 ♀; Fugong Co., Lishadi, 5 km N Shangpa (Fungong), SW of river, 26.95990°N, 98.86726°E, 1217 m, 26 August 2005, sifting deciduous litter in open area with few trees, P. Paquin, PP-5505 (CASENT 9020476, HNU), 2 ♀, 2 juvs ; [same data] (CASENT 9020475, CAS), 1 ♀, 1 juv.

Etymology. Formed from the Chinese words for ground (dī) and silver (bái yín

), referring to the silver corpuscles of this leaf litter spider.

Diagnosis. Male distinguished from other Theridiosomatidae except Ogulnius and the theridiosomatine genera Baalzebub, Epilineutes Coddington, 1986, Wendilgarda Keyserling, 1886 and Theridiosoma by the presence of a filiform embolic apophysis extending beyond the conductor tip (Fig. 10F); embolic division with moderate branching similar to Ogulnius, less complex than the theridiosomatine genera; distinguished from Ogulnius by the juxtaposed posterior median eyes (Fig. 10B; separated by at least their diameter in Ogulnius, Fig. 4C).

Female distinguished from Z. zoma Saaristo, 1996 by the posterior margin of the epigynum, which is more convex in Z. zoma (Saaristo 1996: fig. 1), nearly transverse in Z. dibaiyin (Fig. 11A).

This is the second Zoma species described and the first known from the male.

Description. Carapace dark brown. Sternum brown with dark margin. Legs dark brown, distal segments reddish. Abdomen dark gray with silver patches forming curved transverse stripe (Fig. 10A-C). (Description of coloration based on females; single male specimen teneral.)

Male palp: Palpal tibia with one trichobothrium. Paracymbium elongate with sharp tip, curved near base (Fig. 10E). Tegulum smooth except for rough ventral ridge near tip of conductor in unexpanded conformation (Fig. 10F). Median apophysis lightly sclerotized, much taller than wide, dorsal tip pointed, ventral tip rounded (Fig. 10D). Conductor semitransparent (Fig. 10D). Embolic apophysis long and filiform (Fig. 10F).

Vulva: Epigynum a flat plate with a darkly sclerotized posterior lip, with shallow median and smaller lateral pits (Figs 11A,B, 13A). Spermathecae subspherical, juxtaposed, set in anterior part of epigynum, copulatory ducts wide, follow simple curve (Fig. 11B).

Male (CASENT 9020480): Total length 1.35, carapace 0.65 long, 0.61 wide, clypeus 0.13, sternum 0.33 long, 0.34 wide, coxa IV separated by 1.60 times their width. Posterior median eyes juxtaposed. Macrosetae: Leg I: femur p1, r1, patella d1, tibia d2, p1, r1; Leg II: patella d1, tibia d2, r1; Leg III: patella d1, tibia d1; Leg IV: patella d1, tibia d1. Metatarsal trichobothria: TmI: 0.16; TmII: 0.17; TmIII: 0.19. Leg measurements: see Appendix A.

Female (CASENT 9020482): Total length 1.84, carapace 0.74 long, 0.63 wide, clypeus 0.11, sternum 0.40 long, 0.35 wide, coxa IV separated by 1.29 times their width. Posterior median eyes juxtaposed. Macrosetae as in male. Metatarsal trichobothria: TmI: 0.13; TmII: 0.14; TmIII: 0.20. Leg measurements: see Appendix A. Spinnerets (Fig. 13B-D); AG in shallow depression similar to that found in Epeirotypus (Griswold et al. 1998: figs 24D, 25D)