Two new species of the genera Mysmena and Trogloneta (Mysmenidae, Araneae) from Southwestern China

Abstract Two new spider species of the family Mysmenidae Petrunkevitch, 1928 are reported from Southwestern China, i.e., Mysmena wawuensis sp. n. (male and female) from Sichuan and Trogloneta yuensis sp. n. (male) from Chongqing. Diagnoses and illustrations of the new species are provided.


Introduction
Mysmenidae is a small family of minute araneoid spiders. Although the family Mysmenidae is distributed worldwide, it is one of the least-studied family-level groups among orb-weaving spiders, and its diversity is grossly undersampled due to their small size (0.7-3 mm) and cryptic life style (Lopardo et al. 2011). Mysmenids mainly occur in leaf litter and other cryptic places in very humid habitats (Lopardo & Coddington 2005), and even in caves. Their distribution ranges throughout the tropical or subtropical regions of Eurasia, America and Africa. According to the latest records, a total of 123 species and 23 genera were reported in the family Mysmenidae (Platnick 2013). Up to present, 30 species placed in 9 genera have been described in China (Yin et al. 2004;Ono 2007;Lin and Li 2008;Miller et al. 2009).
The genus Mysmena was erected by Simon in 1894 initially as a genus of the family Theridiidae with the type species Theridion leycoplagiatum Simon, 1879; later transferred to the Symphytognathidae by Forster (1959), and then to the family Mysmenidae by Forster and Platnick (1977). To date, 23 Mysmena species have been reported worldwide (Platnick 2013), including 12 species from China which is about a half of all species of the genus Mysmena (Ono 2007;Lin and Li 2008;Miller et al. 2009).
The genus Trogloneta was established and placed in the family Theridiidae by Simon in 1922 for a minute spider from caves in France, T. granulum ("Troglonata" was misspelled in the original description, see Simon 1926: 313) (Brescovit & Lopardo 2008). Gertsch (1960) transferred this genus to the family Symphytognathidae, and then Forster & Platnick (1977) put it in the family Mysmenidae. Until now there is no consistent diagnosis for Trogloneta, Brescovit and Lopardo (2008) proposed that this genus can be distinguished from other mysmenids by the following combination of features: AME smaller than ALE; one femoral spot on leg I on both males and females; one male clasping spine on metatarsus I; males with highly elevated and conical carapace, and male pedipalp very large. Additional diagnostic characters may include the clustering of eyes around the apex of the carapace in males (Fig. 8A-B; Lin & Li 2008: figs 16A-B, 19A-B) and the abdomen usually pointed dorsal-posteriorly (the exception is T. denticocleari Lin & Li, 2008, which has a globose abdomen).
At present, 9 Trogloneta species are known from America, Europe, Asia and some Atlantic islands (Platnick 2013), including two species reported from China (Lin & Li 2008): one found in caves from the Yunnan-Guizhou Plateau, another found at the canopy of Xishuangbanna tropical rainforest.
In this paper we described two new species of genera Mysmena and Trogloneta from Wawu Mt., Sichuan and Jinyun Mt., Chongqing of Southwestern China, Mysmena wawuensis sp. n. and Trogloneta yuensis sp. n.

Material and methods
Specimens were examined and measured under an Olympus SZX7 stereomicroscope. Further details were studied under an Olympus BX43 compound microscope. All drawings were made using a drawing tube attached to Olympus BX43 compound microscope, and then inked on ink jet plotter paper. Photos were taken with a Canon EOS 60D wide zoom digital camera (8.5 megapixels). The images were montaged using Helicon Focus 3.10 software. Male pedipalpi and female genitalia were examined and illustrated after they were dissected and detached from the spiders' bodies. Vulvae were removed and treated in lactic acid before illustration. To reveal the course of spermatic duct, the pedipalpal bulb was also treated in lactic acid and mounted in Hoyer's Solution. Left pedipalp of male spiders was illustrated. All specimens are preserved in 85% ethanol solution.
All measurements are in millimeters. Leg measurements are given as: total length (femur, patella, tibia, metatarsus, and tarsus). The terminology mostly follows Lopardo et al. (2011). The abbreviations used in text including: AER -anterior eye row; ALE -anterior lateral eye; AME -anterior median eye; PER -posterior eye row; PLE -posterior lateral eye; PME -posterior median eye. All specimens are deposited in the Zoological Department of the School of Life Science, Sichuan University Museum (SCUM) in Chengdu. Description. Male (holotype). Somatic characters see Fig. 1A     Prosoma (Fig. 1A, C): Carapace near round. Cephalic pars elevated, sharply vertical forward and slope backward. Ocular area at apex, dark. Eight eyes in two rows. AME black, others white. ALE and PLE contiguous. AME smallest, ALE largest. ARE slightly procurved, PRE straight. Chelicerae yellow, small, as long as endites (Fig. 1C).

Taxonomy
Legs: Femora pale yellow, other segments yellow proximally, gray distally. Leg formula: I-II-IV-III. Leg I with a distal metatarsal clasping macroseta prolaterally on 1/3 position. Leg I and II with a subdistal sclerotized femoral spot ventrally. Patellae I-IV with a dorsal seta distally. Tibiae I-IV with a dorsal seta proximally, and with 3 trichobothria. Metatarsi I-IV with only one trichobothrium.
Legs: Color, number of trichobothria same as in male, except for leg I without distal metatarsal clasping macroseta prolaterally. Sclerotized femoral spot present at leg I and II as in male. Leg formula: I-IV-II-III.
Distribution. Known only from the type locality (Fig. 13).
Female. Unknown. Distribution. Known only from the type locality (Fig. 13).