Hesperomeryx, a new artiodactyl from the Sespe Eocene, California

Among the several artiodactyls collected in the Upper Sespe Eocene, the new subgenus here described, is clearly the most abundant type. In the fauna recorded at Locality 180 this form exceeds in number all other species; its representation, as a matter of fact, is greater than that of all other individuals combined. No less than 100 individuals are known on the basis of teeth, fragmentary jaws and scattered skeletal elements. While some variation is to be noted, a surprising constancy in structural features characterizes the collection as a whole. For this reason all specimens belonging to this type are referred to as single species.