22 BULLETIN OF THE 



ing them as constituting two genera. To the first of these genera, em- 

 bracing the sea bears, founded in fact on one of the Southern ?ea bears, 

 (? Ar otocephalus Delalandi Gray), he gave the name of Arctocephulus, 

 and to the other, founded on the Southern sea lion (Otaria jubata 

 Blainville), that of Platyrhynchus. These names indicate to some ex- 

 tent the differences seen in the general form of the head, in the 

 two groups. In the first, or sea bears, the muzzle is narrow and 

 pointed ; in the other it is broad, and the aspect is more leonine. The 

 name Platyrhynchus, however, is antedated by that of Otaria of Peron. 

 Besides these differences in the shape of the head, the form of the 

 body in the Arctocephaline species is more slender than in those of the 

 other group. The hind feet, especially, are longer and slenderer, 

 with relatively longer swimming-flaps at the end of the toes. Their 

 size is smaller, and they differ in general color. The Arctocephaline 

 species are also all provided with a dense, soft, thick under-fur, while 

 the others are either entirely without under-fur, or possess it in too 

 small a quantity to render the skins of any commercial value as furs.* 

 These two groups are as well defined as the several sub-families of the 

 Phocidce, and are co-ordinate with them. If the Otariadce constitute a 

 group entitled to family rank, — and the so-called sub-families of the 

 Phocidce have truly a sub-family value, — the Otariadce must be con- 

 sidered as divisible into two sub-family groups, of which the hair seals 

 constitute one and the fur seals the other. 



In respect to what names should be used for their designation, none 

 seem in themselves more appropriate than those derived from the 

 names of the leading genera of these groups, Otariince for the hair 

 seals and Arctocephalince for the fur seals. These names, however, 

 in a slightly altered form (Otariina and Arctocephalina), have been 

 used on different occasions in widely different senses, especially by 

 Gray ; the first for the whole group of eared seals, and afterwards the 

 other in precisely the same sense. Later, both were again used simul- 



* I am aware of the alleged exceptions in the Otarys of Australia : the Zalqphtu 

 lobatus Peters, a true hair seal, having, it is said, considerable under-fur when young. 

 This is probably the case, to a greater or less extent, with the young of all the hair 

 seals prior to the first moult. I feel sure, however, that it is quite different in char- 

 acter from the soft, long, dense fur of the true fur seals. It may be added that the 

 genus Zalrphus is in other respects, as in size and the general shape of the head, 

 somewhat intermediate between the fur and hair seals, though its affinities are decid- 

 edly with the latter. 



