New cave-dwelling armored spiders (Araneae, Tetrablemmidae) from Southwest China

Abstract A new genus and five new species belonging to the family Tetrablemmidae are described from caves in Southwest China, i.e., Sinammaoxycera gen. & sp. n., Singaporemma banxiaoensis sp. n., Singaporemma wulongensis sp. n., Tetrablemma ziyaoensis sp. n. andTetrablemma menglaensis sp. n. The following new combination is proposed: Sinamma sanya (Lin & Li, 2010), comb. n. ex. Shearella Lehtinen, 1981. The relationships of the Sinamma gen. n. with other genera are discussed. Diagnoses and illustrations for all new taxa are given.


introduction
Tetrablemmids are medium-sized (Pacullinae) to small (Tetrablemminae) haplogyne spiders, characterized by a complex pattern of abdominal scuta (Shear 1978;Lehtinen 1981;Jocqué and Dippenaar-Schoeman 2006). They are mainly distributed in the tropical and subtropical regions where they are found in leaf litter, soil, and in caves (Burger et al. 2010). This family has been revised by Lehtinen (1981). Burger et al. (2006) and Burger (2008) studied the functional morphology of the genitalia of the family Tetrablemmidae. A total of 144 species belonging to 30 genera of the family Tetrablemmidae have been described (Platnick 2014).
Chinese tetrablemmids have been studied recently. Five species belonging to four genera from Hainan Province were reported by Tong and Li (2008). Lian (2009) reported one species of the genus Perania Thorell, 1890 from Yunnan Province. Lin and Li (2010) described five more species (two from rainforest habitats in Hainan and three from caves in the Yunnan-Guizhou Plateau). In total, 11 species belonging to eight genera have been reported from China (cf. Platnick 2014).
In the period of October 2010 to August 2011 we found several new and interesting species of the family Tetrablemmidae from Southwest China and in this paper we now describe five new tetrablemmid taxa.

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 an Olympus BX43 compound microscope, and then hand inked on ink jet plotter paper. Photographs were taken with a Canon EOS 60D wide zoom digital camera (8.5 megapixels). The images were combined using Helicon Focus 3.10 software. Male palp and female genitalia were examined and illustrated after they were dissected and detached from the spiders' bodies. Vulvae were removed and treated in KOH solution before examination and illustration. To reveal the course of the sperm duct, the bulbs were treated in lactic acid and mounted in Hoyer's Solution before examination and illustration. Left palp is illustrated unless missing, in which case the right palp is illustrated.
All specimens are acquired from caves by manual collection and preserved in 85% ethanol solution. All specimens are deposited in the Sichuan University Museum (SCUM) in Chengdu and in the Institute of Zoology, Chinese Academy of Sciences (IZCAS) in Beijing.
Female ( Carapace (Figs 1C, H and F) with a pair of cephalic tubercles; cephalic part slightly elevated, clypeus lower than in male; cheliceral horn absent. Legs as in male, except for leg I undecorated.   Abdomen (Figs 1C-D, F; 3A): lateral scutum I anteriorly extending beyond the anterior rim of operculum; preanal scutum anteriorly rugose, covered with sparse serrated setae.
Distribution. Known only from the type locality (Fig. 22).
Singaporemma Shear, 1978 http://species-id.net/wiki/Singaporemma Type species. Singaporemma singularis Shear, 1978 from Singapore. Diagnosis. Distinguished from other tetrablemmids by the swollen palpal tibia, the egg-shaped bulb, the originating position of embolus in male, and by the oval epigynal pit, the central process larger than inner vulval plate in female.
Distribution. Four species are known from China, Singapore and Vietnam before the current study. Etymology. The specific name refers to the type locality; adjective. Diagnosis. This new species is similar to S. halongense Lehtinen, 1981(see Lehtinen 1981, but can be distinguished by the white vestigial eyespots in both sexes (    Carapace (Figs 4A-B, G, E) reticulated, margin rugose; eyes white, vestigial; clypeus sloping forward, marginally rounded; cephalic part flat; sternum finely reticulated, margin rugose, with sparse setae. Legs: cuticle striated; all tibiae with 2 trichobothria, and one on metatarsi I-IV.
Female ( Carapace (Figs 4C-D, H and F) as in male; clypeus slightly lower than in male. Legs: the chaetotaxy as in male.
Variation. Total length from 1.00 to 1.07 in males (n = 6) and from 1.05 to 1.14 in females (n = 10).
Variation. Total length from 1.14 to 1.25 in males (n = 9) and from 1.16 to 1.30 in females (n = 20).   Diagnosis. Tetrablemma is close to Singalangia Lehtinen, 1981 andRhinoblemma Lehtinen, 1981. Tetrablemma is separated from Singalangia by largely different pattern of abdominal plates, by well developed lateral horns of vulva, and by lack of apomorphic modifications of the same type in sternum and epigynal area. It is separated from Rhinoblemma by different types of sexual dimorphism in the male clypeal area and chelicerae.
Female (paratype). Coloration and modifications as in male, but cephalic tubercle and cheliceral horn absent.
Carapace (Figs 13A-B, E and G): most of surface reticulated, marginally rugose; ocular area slightly raised, located at center, with two long setae between PLEs; clypeal area distinctly convex, margin rounded; cheliceral horn thin, sharp, distally curved; sternum finely reticulated, strongly sclerotized at margin. Legs: cuticle striated and granular; femur I not swollen; tibiae I-III with 3 trichobothria, 4 on tibia IV, and metatarsi I-IV with one trichobothrium.
Distribution. Known only from the type locality (Fig. 22).