Two new spider species of the genus Chrysso O. P.-Cambridge, 1882 (Araneae, Theridiidae) in Hainan Island, China

Abstract Two new spider species of the genus Chrysso O. P.-Cambridge, 1882 are reported from Hainan Island, China, Chrysso bifurcasp. n. (male, female) and Chrysso bicuspidatasp. n. (male, female). Chrysso bimaculata Yoshida, 1998is recorded from China for the first time.


Introduction
The genus Chrysso was erected by O. P. -Cambridge (1882). It was regarded as a junior synonymy of Theridion Walckenaer, 1805, and removed by Bryant (1940). Levi and Levi (1962) considered this genus as a senior synonym of Arctachaea Levi, 1957, Argyroaster Yaginuma, 1958and Meotipa Simon, 1894, but Deeleman-Reinhold (2009 removed the genus Meotipa from the synonymy of Chrysso. Until now no large revision of this genus has been done. However, Agnarsson (2004) listed 10 autapomorphies of the Chrysso in his phylogeny, these characteristics are putative Chrysso synapomorphies.
During the examination of spider specimens collected from 2007 to 2009 in Hainan Island, China, two new species, Chrysso bifurca sp. n. and C. bicuspidata sp. n. were recognized and are described here. C. bimaculata Yoshida, 1998, known from Japan previously, is newly recorded from Hainan, China.

Material and methods
All specimens were kept in 75% ethanol and examined, drawn and measured under a Tech XTL-II stereomicroscope equipped with an Abbe drawing device. Carapace length was measured medially from the anterior margin to the rear margin of the carapace. Eye sizes were measured as the maximum diameter of the lens in dorsal or frontal view. MOA length was measured medially from the anterior margin to the rear margin of MOA. Leg measurements are given as: total length (femur, patella, tibia, metatarsus, tarsus). Epigynes were cleared in warm potassium hydroxide (KOH) and transferred to 75% ethanol for drawing. The labeling of the palpal sclerites is adopted following Agnarsson (2004). All measurements are in millimeters. All specimens studied are deposited in the Museum of Hebei University (MHBU), Baoding, China. Diagnosis. Males can be distinguished from other Chrysso species by the following characters: apex of cymbium bifurcate; embolus short and thin; theridiid tegular apophysis erect, with obtuse apex (Figs 3-4). Females differ from other Chrysso species by the bigger and oval spermathecae, and the longer and winding copulatory ducts, differ from C. octomaculata (Bösenberg & Strand, 1906) by the process of copulatory ducts (Fig. 6).

Abbreviations
Etymology. The species name refers to bifurcate apex of cymbium. Description. Male (holotype). Total length 2.70: cephalothorax 1.26 long, 1.08 wide; abdomen 1.44 long, 0.99 wide, 0.90 high. Carapace yellow, longer than wide, lateral margin with thin black striations. Only anterior part with several gray setae. Cervical groove distinct. Median furrow almost triangle, yellowish. Each eye with a black ring. Both the eye rows recurved from dorsal view ( Fig. 1). Diameters of eyes: AME 0.12, ALE 0.10, PME 0.10, PLE 0.10. Interdistances of eyes: AME-AME 0.10, AME-ALE 0.08, ALE-ALE 0.64, PME-PME 0.10, PME-PLE 0.14, PLE-PLE 0.66, ALE and PLE closed to each other. MOA long 0.29, front width 0.34, back width 0.31. Clypeus 0.32 high, yellow and furnished with few short gray setae. Chelicerae armed with sparse gray setae, promargin with 2 teeth, fangs short and thin. Anterior margin of endites armed with gray scopula. Labium armed with sparse long black setae. Sternum furnished with sparse black setae, its anterior margin lightly procurved. Legs yellow, patella, metatarsus and the base of femur and tibia reddish-brown. Abdomen oval, longer than wide and armed with brown setae. Dorsum yellowish, armed with six pairs of irregular black patches, posterior with a median black patch (Figs 1-2). Venter yellowish, with a black median patch. Anal tubercle yellow. Spinnerets yellow.
Variation. The lateral part of dorsal abdomen of some females examined with eight to eleven pairs of irregular black patches. Males total body length from 2.64-2.80, female total length from 3.28-3.35.
Distribution. China (Hainan).  Zhu, 1998 andC. oxycera Zhu &Song, 1993 in the general shape of the palpal organ, but differs from them by the wider embolus (Figs 8-9). Females differ from all other Chrysso species except C. viridiventris Yoshida, 1996 by the epigynum with a big atrium and a large posterior lobe. It differs from C. viridiventris by the bigger spermathecae and shorter copulatory ducts (Figs 10-12).
Etymology. The species name refers to the shape of embolic tip. Description. Male (holotype). Total length 1.84: cephalothorax 0.92 long, 0.71 wide; abdomen 0.92 long, 0.82 wide, 0.92 high. Carapace longer than wide, yellowish, lateral margin with thin black striations, anterior median with a triangular black patch. Only anterior part with several gray setae. Cervical groove yellowish. Median furrow yellowish, almost triangle. Each eye with a black ring. Both the eye rows recurved from dorsal view (Fig. 7). Diameters of eyes: AME 0.05, ALE 0.04, PME 0.04, PLE 0.04. Interdistances of eyes: AME-AME 0.10, AME-ALE 0.03, ALE-ALE 0.33, PME-PME 0.10, PME-PLE 0.08, PLE-PLE 0.38, ALE and PLE closed to each other. MOA long 0.13, front width 0.18, back width 0.18. Clypeus 0.20 high and furnished with few short gray setae. Chelicerae armed with sparse gray setae, promargin with 2 teeth, fangs short and thin. Endites, labium and sternum yellowish. Anterior margin of endites armed with gray scopula. Sternum furnished with sparse gray setae. Legs yellowish, the end of tibia with gray spots. Abdomen oval, longer than wide and armed with brown setae. Dorsum yellowish, anterior part with a pair of black patches (Fig. 7). Venter yellowish. Spinnerets yellowish.
Apical cymbium of male palp acuate; embolus big, thick, and end with a thin ramus; conductor membranous, falciform from ventral view; apex of median apophysis with some small tubers (Figs 8-9).
Female genitalia lightly sclerotized, and with a circular atrium and a large posterior lobe; spermathecae big, oval; copulatory ducts short, thick and connected with spermathecae from anterior part; each fertilization duct with a global head (Figs 10-12).
Variation. The anterior part of dorsal abdomen of some species examined with a pair of black patches, some species without. Males total body length from 1.73-1.88, females total length from 2.22-2.35.
Embolus of male palp small, thin and wind; conductor wind, membranous; median apophysis big, posterior part with a small tuber from prolateral view (Figs 14-15).
Variation. The amount of white patches and black patches of dorsal abdomen variated from two pairs to three pairs. Males total body length of some species examined from 1.40-1.55, females total length from 1.68-1.82.