ABSTRACT: The western North American genus Lionepha is shown to contain at least 11 species through a combination of eight-gene species delimitation analyses and morphological study. In order to confirm the names of several species, we sequence DNA of primary types of several names, including a LeConte lectotype collected in the 1850s, using next-generation sequencing. We examine chromosomes of eight species, and show that all have 12 pairs of autosomesand an X0/XX sex-chromosome system. The following species are described as new: Lionepha australerasa, L. kavanaughi, L. lindrothi and L. tuulukwa. The name Lionepha erasa is shown to belong to a relatively rare, western species ranging from Oregon through Alaska; the common, widespread species previously known as Lionepha erasa now takes the name L. probata. Bembidion chintimini, B. lindrothellus and B. lummi are synonymized with L. erasa. We provide tools to identify specimens to species, including illustrations, diagnoses and distribution maps. DOI: 10.1093/zoolinnean/z1z167.

ADDITIONAL KEYWORDS: Trechinae, Bembidiini, species delimitation, chromosomes, ancient DNA, ground beetle