Two new species of the genus Trilacuna from Chongqing, China (Araneae, Oonopidae)

Abstract Two new species of the genus Trilacuna Tong & Li, 2007, T. simianshan Tong & Li, sp. n. and T. songyuae Tong & Li, sp. n., are described from Simianshan Natural Reserve, Chongqing, China.

In this paper two new Trilacuna species, T. simianshan Tong & Li, sp. n. and T. songyuae Tong & Li, sp. n., collected in the Simianshan Mountains, are described and illustrated.

Materials and methods
The specimens were examined using a Leica M205C stereomicroscope. Details were studied under an Olympus BX51 compound microscope. Photos were made with a Canon EOS 550D zoom digital camera (18 megapixels) mounted on an Olympus BX51 compound microscope. Vulvae were cleared in lactic acid. For scanning electron microscopy (SEM), specimens were air-dried and uncoated. Pictures were taken with a Hitachi TM3030. All measurements were taken using an Olympus BX51 compound microscope and are in millimeters.
The following abbreviations are used in the text and figures: Etymology. The specific name is a noun in apposition taken from the type locality.
Diagnosis. This new species is similar to T. rastrum and can be distinguished by two long outgrowths of the embolus system and the long cone-shaped structure in females vs. the embolus system with a short ribbon-like outgrowth and a rake-shaped protuberance, and a simple stick-shaped sclerite centrally on the female genitalia of T. rastrum (see Tong and Li 2007: figs 6-10).
Genitalia. Epigastric region with sperm pore (sp) small, oval, rebordered, situated between anterior spiracles; with a small hole (slh) between the posterior spiracles    (Fig. 2C, D). Bulb oval, stout, tapering apically. Embolus system (Fig. 3B, D, F) complex, with two long, strongly curved outgrowths (ogr1 and ogr2); the surface of the embolus system bearing numerous small "papillae". The base of the embolus system with a wing-like, membranous projection (mp) in prolateral view and a circular projection (cp) covered with scales in retrolateral view; middle part of the embolus system with a rectangular projection (rp) in dorsal view. Female. As in male except as noted. Slightly larger than male. Body length 2.28; carapace 0.99 long, 0.85 wide; abdomen 1.36 long, 0.89 wide. Postepigastric scutum long. Posterior spiracles connected by groove (Fig. 5B).
Female genitalia. Ventral view (Fig. 5H): Middle part of posterior margin of epigastric scutum much extended posteriorly (pe); surface without external features. Dorsal view (Fig. 5I): with a very long, nearly cone-shaped structure (css), at the posterior end of the cone-shaped structure is a slender line-like structure (sls) originating and extending anteriorly. Transverse bars with two relatively long, lateral apodemes.
Distribution. China (Chongqing). Etymology. The specific name is after Miss Songyu Lyu (吕松宇), one of the collectors of this species.

Trilacuna songyuae
Diagnosis. The new species is similar to T. hansanensis Seo, 2017. Both species have an elevated ridge on the posterior part of the male sternum, but can be distinguished by the long oval bulb, the very long setae (nls) on the prolateral surface of the male palpal tibiae and the two small, spear-like setae (sps) on the basal part of the prolateral surface of male palpal cymbium. Trilacuna hansanensis has a pear-shaped bulbus, and there are no special setae on the male palpal tibia or cymbium (see Seo 2017: figs 1A-K).
Genitalia. Ventral view (Fig. 10H): surface without external features, a dark knob-like marking (dk) can be seen through the cuticle. Dorsal view (Fig. 10I): with a very small, cone-shaped structure (css). Transverse bars with two relatively long, lateral apodemes.