Crinodessus amyae, a new nearctic genus and species of predaceous diving beetle (Coleoptera:Dytiscidae:Hydroporinae:Bidessini) from Texas, USA

Crinodessus amyae n. gen. and n. sp. is described from southwestern Texas, U.S.A. The genus is separable from all other genera of Bidessini by the combination of 1) cervical line posterior of and separated from posterior margin of the eye, 2) separation of the genal line from the ventral margin of the eye broad, 3) apical segment of the paramere elongate, 4) dense microreticulation on the ventral surface consisting of minute, isodiametric cells, 5) relatively large size for members of the tribe, 6) distinctive habitus with the pronotum cordate and the body elongate and depressed, and 7) anterior clypeal margin extended anteriorly and prominently angulate. The similarity in habitus and other characters between Crinodessus and Boongurrus Larson is hypothesized to be a result of homoplasy due to similar behavior and common adaptation to a similar habitat. Liodessus Guignot is tentatively proposed to be the sister genus of Crinodessus.