(…) The Dall porpoise, Phocoenoides dalli (True), occupies a rather restricted range in the northern Pacific. On the American side this extends from the Aleutian Islands to Santa Barbara Channel, California, but the known occurrences south of Canadian waters are so few that they may be of an extralimital or vagrant nature. Certainly the center of abundance lies in the coastal waters of northern British Columbia and southeastern Alaska.
There seems to be little published information concerning the habits, anatomy and variation in this species. A paper by Benson and Groody (1942, p. 41), recording the capture of a specimen of this porpoise in San Francisco Bay, California, lists 13 known specimens in the museums of America, five of which are skeletons. There are no published references to specimens from Canadian waters. However, in the summer of 1939 through the active interest of Lieutenant P. W. Martin R.C.N.V.R. of Victoria, B. C. and T. T. McCabe of Berkeley, California, the British Columbia Provincial Museum obtained five complete skeletons of the Dall porpoise from the waters adjacent to Queen Charlotte Sound, B. C. One of the porpoises was sent to the museum frozen, for subsequent casting and dissection. Four of them were accompanied by excellent photographs.
On the basis of these specimens, three males and two females, it has been possible to undertake a preliminary survey of variation in certain external and skeletal features, while field notes accompanying the specimens contribute in a small way to the known life history of the species. (…)