Prismognathus arcuatus (Houlbert, 1915)

(Figs. 65, 95, 113, 132, 150–151, 186–187, 212, 235)

Eligmodontus arcuatus Houlbert, 1915: 17 [type locality: Ta-tsien-Lou (now Kangding, western Sichuan)], Fig. 1, male; Fig. 2, male head; Mizunuma & Nagai 1994: plate 147, Fig. 107, male “ type ” from China (probably not type material), plate 155, Fig. 221, male from “ Nepal ” (incorrect data).

Prismognathus arcuatus: Nagai 2005: 35; Fujita 2010: 169, plate 101, Fig. 508-1, male from Sichuan.

Material examined. CHINA: Sichuan: 6 3, 1 Ƥ, Ya-an City, Yingjing County, Siping, VII.2007, H.-C. Shan leg.; 2 3 (CHH, CYXW), Hanyuan County, Nimei, VII.2005, C.-J. Dai leg.; 1 3 (IEAS), Shimian County, Liziping Nature Reserve, Gongyihai station, 2100m, 22.VII.2007, W.-X. Bi leg.

Identification. This species was originally described from western Sichuan and a male specimen was illustrated. There cannot be confusion in identifying this species due to the peculiar male characters. The male specimen illustrated and labeled by Mizunuma & Nagai (1994: plate 147, Fig. 107) as the “ type ” from “ China ” is unusual, with an anteriorly-divergent preocular margins of the head. The type specimen originally illustrated in the description paper has the preocular margins of the head parallel. Specimens from Sichuan examined by us match with the original description and illustration.

The female is here described and illustrated for the first time. Only a single female was examined by us, and it was identified as P. arcuatus due to the protruding lateral angles of the pronotum and the obsolete spermathecal gland in the female genitalia, which are very similar to those of the close species, P. haojiani .

Distribution. Western Sichuan.