776 DR. J. E. GRAY ON THE [ Dec. 2, 



4. On the Skulls of Japanese Seals, with the Description of 

 a New Species, Eumetopias elongatus. By Dr. J. E. Gray, 

 F.R.S. &c. 



[Received October 28, 1873.] 



The British Museum has recently received from Mr. Arthur 

 Adams's collection two specimens of skulls of Seals from Japan. The 

 first is a young specimen of an Eared Seal, and was taken for, and 

 believed to be the young of, a Seal of which I described and figured the 

 skull in the P. Z. S. 1872, p. 738, figs. 2 and 3, which we received 

 from Mr. Gerrard, jun., as coming from Japan, but which he now 

 informs me was obtained from Mr. Arthur Adams's collection. It 

 is evidently the young of the same species, though the older speci- 

 men, like the skulls which we have got of Eumetopias stelleri from 

 California, have a space between the fourth and sixth teeth, as if a 

 tooth were absent, as I observed in my description of the genus. 

 The young skull now received has a fifth tooth present, and chiefly 

 differs from the genus Gypsophoca from the South Seas in the fifth 

 and sixth teeth not being so distinctly behind the front part of the 

 zygomatic arch as in that genus. 



The reception of the young skull from Japan makes it very 

 doubtful if the species of Eumetopias from that coast is the same 

 as the true Eumetopias stelleri from the N.W. coast of America; 

 for both the old and young skulls are very much narrower, com- 

 pared with their length, and especially the skull of the elder 

 animal. The orbits are smaller. The skulls of the young animals 

 are the most distinct ; for the skull of the young animal from Japan 

 is solid and much more developed than the much larger young 

 skull from California, in the Museum, figured in the P. Z. S. 1872, 

 p. 740, figs. 4 and 5, where the great width of the zygomatic arch 

 and the very large size of the orbit are most striking, and the skull 

 is very light and thin, and, like the teeth, very imperfectly de- 

 veloped. These differences are too great, I think, to be sexual ; 

 therefore I am inclined to think that there are two species of the 

 genus Eumetopias. 



1. Eumetopias stelleri. 



Eumetopias stelleri, Gray, Suppl. Cat. Seals and Whales, p. 30 ; 

 P. Z. S. 1872, p. 740, figs. 4 & 5 (skull, young) ; Allen, Bull. Comp. 

 Anat. and Zool. vol. ii. p. 44, t. 1 & 2 (skulls). 



Arctocephalus monteriensis, Gray, P. Z. S. 1859, p. 358, t. 72 

 (skull). 



A. calif or nianus, Gray, Cat. Seals and "Whales, 1866, p. 51 (skull 

 only of young). 



N.W. Coast of America ; California ; Behring's Straits. 



2. Eumetopias elongatus. (Figs. 1 and 2, pp. 777, 778.) 



E. stelleri, Gray, P. Z. S. 1872, p. 738, figs. 2 & 3 (skull, nearly 

 adult). 



