Through the kindness of a correspondent in Southern California, the writer recently acquired a series of 320 superb examples of Dentalium neohexagonum S. and P. collected from the Fernando formation of that state. The following somewhat detailed account of the variations occurring in the collection may prove of interest to students of the Scaphopoda. Our study of this series is supplemented by the addition of other material of the species, collected by Charles Sternberg, from the Pleistocene in the vicinity of San Quintin, Baja California, Mexico, and a few examples of the species, now found living off the California coast, dredged by Henry Hemphill.