During a recent exploration of caves in western Ciscaucasia there was collected, among others, a new species representing a new genus of Trechini (Coleoptera, Caraboidea), the description of which is given here; it has been named Birsteiniotrechus ciscaucasiens n.gen., n.sp., in memory of Prof. J.A. Birstein, famous Soviet biospeleologist, the founder and promotor of the “Biospeologica sovietica” series who passed away recently (cf. I.J.S., 4, part.2). The interest of Birsteiniotrechus lies in the fact that, until now no troglobite or endemic species of Trechini was known from the Ciscaucasian mountains; this genus belongs to the phyletic series of Neotrechus and is nearly allied to Troglocimmerites, but differs from it by its labial characters.