Systaria Simon, 1897

Zhang, Feng, Fu, Jianying & Zhu, Mingsheng, 2009, First report of the sac spider genus Systaria Simon (Araneae: Clubionidae) from China: Systaria hainanensis sp. nov. and Systaria mengla (Song & Zhu, 1994) comb. nov., Zootaxa 2305, pp. 51-60 : 52-53

Systaria Simon, 1897

Systaria Simon 1897a: 87 ; Lehtinen 1967: 237; Deeleman-Reinhold 2001: 202. Hebrithele Berland 1938: 137 [synonymised by Deeleman-Reinhold (2001)]. Type species. Systaria drassiformis Simon, 1897 , by original designation.

Diagnosis. Systaria are medium-sized ecribellate, entelegyne sac spiders with two claws, and not armoured. Diagnostic somatic characters of the genus include the combined presence of enlarged and dark AME, slightly procurved PER, a well-marked thoracic groove, notched trochanters, thick tarsal claw tufts, widely separated (by almost their diameter in females, less in males), slightly tapering ALS, and an elongated distal segment on the PLS (but shorter than the proximal segment) ( Deeleman-Reinhold 2001).

The weakly sclerotised epigyne has openings in a posterior window or depression, which is lined with a sclerotised rim anteriorly. The openings are often united by a transverse arch. Two concave copulatory openings are located postero-medially near the epigastric furrow. The spermathecae are placed posteriorly in the vulva and the bursae are situated lateral to the copulatory openings. The spermathecae are smaller than the bursae and both are connected to the copulatory opening through a thick connecting duct. The fertilization ducts are short and arise from the postero-lateral ends of the spermathecae. The male palpal tibia has a simple retrolateral apophysis. The cymbium has an incised basal margin with a proximal retrolateral groove closely opposed by a tibial apophysis. The sperm duct is comparatively strong and lines the distal and lateral contours of the tegulum. The spiniform embolus originates from the prolateral tegulum, is long and reaches beyond tip of tegulum and has a membranous conductor ( Deeleman-Reinhold 2001).

Spiders in this genus can be distinguished from other similar genera distributed in Southeast Asia (for example, Tamin Deeleman-Reinhold, 2001 , Xantharia Deeleman-Reinhold, 2001 and Palicanus Thorell, 1897 ; all currently listed in Miturgidae ) by enlarged AME and slightly procurved PER. It is also separated from Tamin by the dense tarsal claw tufts, by the eye group that is more than two thirds of the head width and by the male ALS that are not longer than the female’s. It is further separated from Xantharia by the lack of endite folds or impression in the middle, by leg I not thicker than leg II-IV, by the dense tarsal claw tufts, and by the anterior tibiae with paired ventral spines. It is separated from Palicanus by the strong cylindrical sperm duct of the tegulum, by the shorter distal than basal segments of the PLS and by the lateral concavities of the endites ( Deeleman-Reinhold 2001).

Remarks. Deeleman-Reinhold (2001) placed Systaria in her new subfamily Systariinae, treated within the Clubionidae . However, Platnick (2009) lists Systaria in the Miturgidae following Lehtinen (1967: 237). We here follow Deeleman-Reinhold (2001) by listing Systaria in the Clubionidae but recognise taxonomic problems as other genera originally included in the Systariinae by Deeleman-Reinhold (2001), including Tamin , Xantharia and Palicanus , remain in the Miturgidae ( Platnick 2009) . It is beyond the scope of this study to address the family placement of these genera as we were not able to examine respective material. However, the generic listing of Systaria in the Clubionidae is based on a number of characters such as the non-armoured habitus and, more importantly, genital characters such as the simple male palp, i.e. tegulum usually with embolus and conductor only, median apophysis rarely present and such as the epigynum characters, i.e. the presence of a pair of thick-walled spermathecae and a pair of thin-walled bursae both of which connected with copulatory opening through a T-shaped duct. We agree with Deeleman-Reinhold (2001) who suggests that “…, it must be confessed, is not a completely satisfactory classification either, but at present this seems to me the best solution…”. There is an urgent need for a worldwide revision of the two families.