Rhabdophis chiwen
Range
Sichuan, China (endemic): Jiguan Mountain in Chongzhou and Tianquan County
Size
Males 404–431 mm; females 409–476 mm snout-vent
The Chiwen keelback (Rhabdophis chiwen) is a keelback snake endemic to Sichuan, China, known from its type locality, Jiguan Mountain in Chongzhou, and from neighbouring Tianquan County. (The Reptile Database; Wikipedia, general species account)
Adult males measure 404–431 mm and adult females 409–476 mm in snout-vent length. (Wikipedia, general species account)