4. Horniella falcis Yin and Li

Figs 7 B, 9; Map 1

Horniella falcis Yin & Li, 2010 (in Yin, Li & Zhao, 2010: 249).

Type material examined (1 ♀). Holotype, ♀, labeled ‘ CHINA: Guizhou Prov., Suiyang County, Kuankuoshui N. R., Baishaogou, alt. 750–900 m, 05.vi.2010, Yin & Zhai leg. [28°17’19’’N, 107°10’56’’E, leaf litter, sifted] / Holotype [red], ♂ [actually a female], Horniella falcis sp. n., det. Yin & Li, 2010, SNUC’.

Supplementary description. Male. Unknown.

Female (Fig. 7 B). Length 3.77 mm. Head longer than wide, HL 0.76 mm, HW 0.67 mm; anterolateral genal projections (Fig. 9 C) distinct, anterior margins obliquely concave; median sulcus between antennal tubercles short; scapes (Fig. 9 B) simple at basolateral margins; clubs (Fig. 9 A) loosely formed by apical three moderately enlarged antennomeres; venter with pair of slender lateral spines (Fig. 9 D). Maxillary palpomeres II stout, broadened at near middle. Each eye composed of about 35 facets. Pronotum slightly longer than wide, PL 0.74 mm, PW 0.71 mm.

Elytra wider than long, EL 0.93 mm, EW 1.38 mm; discal striae reaching about apical 4/5 of elytral length. Protrochanters (Fig. 9 E) each with one short ventral spine, profemora (Fig. 9 E) each with two ventral spine, protibiae (Fig. 9 F) simple; mesotrochanters (Fig. 9 G) lacking spine, mesofemora simple, mesotibiae (Fig. 9 H) simple; tarsomeres II normal, not extending to beneath tarsomeres III. Abdomen large, AL 1.34 mm, AW 1.40 mm, tergite IV (first visible tergite) with short, thin median carina reaching 1/3 tergal length, lacking discal carinae, tergite V lacking median carina, tergite VII with large apicomedian process. Genital complex (Figs 9 I–K) with membranous trapezoidal apical portion and more strongly sclerotized, transverse basal portion.

Differential diagnosis. This species is provisionally placed as a member of the H. centralis group though only a single female is known. The obliquely concave anterior margins of the anterolateral genal projections in H. falcis are only found in H. schuelkei sp. n. and H. nakhi sp. n. (both described below), which may indicate a close relationship between these species. The female of Horniella falcis can be quickly separated from that of H. nakhi by the presence of a large process at apicomedian portion of the tergite VII, which is lacking in the latter species. Only a single male is currently available for H. schuelkei, its relationship with H. falcis remains unclear. Since the distance between the type localities of H. falcis and H. schuelkei is much greater than that between H. nakhi and H. schuelkei, the former two species are most unlikely conspecific.

Comments. The holotype of this species is actually a female, which was erroneously treated as a male in the original description of Yin et al. 2013.

Distribution. Southwest China: Guizhou (Map 1).

Collection notes. The single female was collected from sifted litter samples in a broad-leaved forest.