MUSEUM OF COMPARATIVE ZOOLOGY. 39 



Dr. Gray, in his various papers published since the appearance of Pro- 

 fessor Peters 's papers, has not only recognized as genera all the genera 

 and subgenera previously proposed by Gill and Peters, including Arcto- 

 phoca, with essentially Professor Peters's first diagnosis of it (including 

 the dental formula !), but has added three others {Euolaria, Gypsopkoca, 

 and Neophoca). Taking into account the nature of the diagnostic 

 characters of his pseudo-genera given in his last synopsis of the family * 

 his classification is too palpably arbitrary to require a detailed review. 



Of the Species. — For a long period the northern sea lions were by 

 most writers regarded as specifically identical with the southern sea 

 lions, and the northern sea bears with the southern sea bears. Peron 

 in 1816 first called attention to the fact that the northern and southern 

 sea lions and sea bears were distinct species. During the following 

 twenty-five years many naturalists of high authority still regarded 

 them as identical, whilst others considered them as distinct. In 1840 

 they were for the last time seriously confounded ; but until within the 

 last four years the two species of Zalophus, the one northern and the 

 other southern, have been regarded as one. It is now generally be- 

 lieved, however, that in no case is the same species found on both sides 

 of the equator.! In Peron's time there were commonly believed to be 

 but a single species of sea lion and a single species of sea bear. He 

 however -affirmed that as many as twenty species of sea bears alone 

 were confounded under that name. Since that time many nominal 

 species have been described, — doubtless partly in consequence of 

 Peron's remark, — until the number of distinct names applied to the 

 different sea lions and sea bears exceeds fifty, while probably the num- 

 ber of veritable species is not more than ten. This, in fact, is the num- 

 ber now most commonly recognized. In consequence of the early con- 

 founding of the northern with the southern species, an extraordinary 

 complication of synonymy has resulted, several of the earlier names 

 having been applied by different writers to several different species. 

 The synonomy of some of these species hence embraces a list of ten 

 to fifteen different and variously applied names. 



Of the hair seals, four apparently unquestionable species are now well 



* Ann. and Mag. Nat. Hist., 4U) Series, Vol. IV, p. 269. This synopsis has already 

 been quoted in full on p. 35. 



t See further remarks on this point below, under the head of " Geographical Distri- 

 bution." 



