i po 2.] Allen, North Pacific Phocida. 493 



and the lower molar 3-cusped. The fourth (No. 21476) has 

 the teeth heavier, much more crowded, and the lower molar 

 is 4-cusped. 



There is nothing to suggest, in view of the normal variability 

 of the skulls and teeth in this and allied groups of seals, that 

 the above enumerated ten skulls are not all referable to the 

 same species. They are all 'young adults,' except the broken 

 Puget Sound skull and the Yakut at specimen, which are 

 adult, but not old. 



In addition to the above are three skulls from the Pribilof 

 Islands (Nat. Mus. Nos. 15276, 49550, 101330). The latter is 

 much the younger and seems to be a female, on the basis of 

 its light structure, small and non-obliquely set teeth, but the 

 lower molar is strongly 4-cusped, a feature more commonly 

 found in the male. Skull No. 49550 is larger and also much 

 older, with the teeth heavier and more crowded, and the lower 

 molar is tricuspid. No. 15276 is a very old skull (without 

 lower jaw), and the teeth are very much worn, little but the 

 roots being left. Its general appearance indicates it to be an 

 extremely old male. The teeth, however, all stand in a 

 straight line. 



No. 6157 (Mus. Comp. Zopl.), from Santa Barbara Isl- 

 ands, California, is an exceedingly old, heavily ossified skull, 

 almost beyond question male. The teeth are exceedingly 

 heavy and very little worn; pni2 and pm3 are very obliquely 

 set in both jaws ; the lower molar is distinctly 4-cusped on the 

 left side and indistinctly so on the right side. Compared with 

 No. 15276 from Pribilof Islands, it is more heavily ossified, 

 the teeth are much larger, and pm2 and pm3 much more 

 obliquely set; the teeth are not much worn, while in the 

 Pribilof skull they are exceedingly worn. 



As these pages are passing through the press I have re- 

 ceived from Dr. C. Hart Merriam, Chief of the Biological 

 Survey of the U. S. Department of Agriculture, four adult 

 skulls two male and two female of Phoca collected at San 

 Geronimo Island, oif northern Lower California, by Mr. A. W. 

 Anthony, in September, 1896, for the Biological Survey. 

 These skulls agree closely with the Santa Barbara skull above 



