Abstract Bembidion perspicuum LeConte is a species distinct from B. transversale Dejean, with which it has been synonymized in the past. In the United States, B. perspicuum occurs from Oregon through Texas along the shores of rivers and creeks. We show that it is consistently different at 40 bases in DNA sequences of cytochrome oxidase I and 4 bases in 28S ribosomal DNA, as well as in subtle morphological characters. In addition, we review the classification of related species in the B. transversale and B. mexicanum species groups in America north of México. In the United States and Canada, the B. transversale group consists of B. transversale, B. perspicuum, and B. sarpedon Casey; the B. mexicanum group consists of B. mexicanum Dejean, B. lugubre LeConte, and B. pernotum Casey.