GENERAL HISTORY AND SYNONYMY. 579 



to Phoca vitnlina in hiscom]>arisons of PJioca nummularis with , 

 other species, the distinctive characters given, so far as they 

 rehite to the sk\ill, point decidedly toAvard P. vitulina, especially '? 

 as respects the dentition, the width of the facial region, etc. The 

 differences in the lower jaw, as compared with that of P. fcetida 

 show its closer similarity to that of P. vitulina. and the larger, 

 thicker, and more closely set teeth, with their larger and more 

 acute cusps are also differences that point in the same direction. 

 It is to be noted, however, that neither of these writers alludes 

 to the mode of implantation of the teeth, but had they been set , 

 obliquely as is usually (not always) the case in P. vitulina^ it is 

 hardly to be supposed that Gray would have failed to so state. , 

 As already noted, in P. vitulina the size of the teeth, their mode \ 

 of insertion, and the width of the anterior or facial portion of 

 the skull are subject to considerable variation, the teeth being 

 sometimes set end to end in a straight line, and even with slight 

 spaces between them. Since, however, they are commonly more 

 obliquely and more closely set in young skulls than in adult 

 ones, it seems hardly probable that three young skulls of this ' 

 species would by chance be found to agree in having the teeth in- ' 

 serted in a straight line, if, indeed, they were all sufficiently in- jj ! 

 tact to show the dentition. The skull from Plover Bay, Behring's 

 Straits (No. 6783, Kat. Mtis.), already described {antea, p. 572), 

 seems to agree very closely with the characters given by Gray , 

 for Temminck's P/wc<x nummularis { = '''-Pagomys I largha^^^ Gray, 

 1866), yet I find in a large series of skulls (more than twenty ', 

 have been examined) of Phoca vitulina a complete gradation 

 between this extremely attenuated example and the very thick, 

 heavy skulls of the oldest males. 



While I do not deem it improbable, in view of all the facts of 

 the case, that a species distinct from Phoca vitulina but of the ^ 

 same general type of structure, though slenderer, may exist in 

 the IS'orth Pacific, and which may be referable to Temminck's , 

 P. nummularis, I feel disposed to leave the question open and j 

 for the present provisionally consider P. nummularis as a pos- 

 sible, if not a probable, synonym of P. vitulina. % 

 The Phoca concolor of DeKay, unquestionably based on the i 

 light phase of the common Harbor Seal of our eastern coast, 

 has been referred by nearly all European writers, often with \ 

 expressions of doubt but frequently with entire positiveness, to ; 

 Phoca fcetida, or the Ringed Seal, in consequence of its light 

 silvery-gray color. 



