Genus Zygethobius Chamberlin, 1903

Zygethobius, the only North American genus of the tribe, can be distinguished from Lamyctes in lacking a spiracle on the first leg-bearing segment, by having 38–43 antennal articles, by bearing coxal pores on the 11th leg-pair, and by having at least tergites 9, 11 and 13 produced. All tarsi are biarticulate, while only 13–15 are biarticulate in Lamyctes . Chamberlin (1912) divided this genus into two subgenera, with the subgenus Zantethobius Chamberlin, 1911 for the single eastern U.S. species. Zantethobius was based on the supposed presence of a distal tibial spine on the 15th leg-pair (Chamberlin 1911). Crabill (1981) examined numerous specimens of Z. pontis from near the type localities, and found that all specimens in fact lacked such a spine, and so synonymized Zantethobius with Zygethobius . However, the name remains available if future work shows that Z. pontis is generically distinct from the western species of the genus.