76 THE VOYAGE OF H.M.S. CHALLENGER. 



Eumetopias, Gill. 



Eumetopias, Gill, Proc. Essex Inst., vol. v., 1866. 



This genus was established by Gill, and Steller's Sea Lion is by some zoologists the 

 only species which is included in it. Peters, however, has placed in this genus Steller's 

 Sea Lion, the Californian Sea Lion, the species Eumetopias cinereus from the Australian 

 Seas and the species Eumetopias hookeri from the Auckland Islands. The characters as 

 laid down by Peters are as follows : — " Ears longer than in Otaria, but with similar 

 hair; posterior border of the hard palate far removed from the hamular processes." 



Eumetopias stelleri (Lesson). Steller's Seal or Sea Lion. North Pacific. 



Otaria stelleri, Less., Diet. Class. Hist. Nat., t. xiii. p. 420, 1828. 



Gray, Brit. Mus. Catal., p. 10, 1866. 

 Eumetopias stelleri, Allen and Bryant, Bull. Mus. Comp. Zool., vol. ii. p. 46, 1871. 



Vertex sinuous or "^-shaped in outline from behind outwards. 



PremaxUla articulates with about anterior third of outer border of nasal. Anterior 

 nares well in front of infraorbital foramina. Postorbitals very large and quadrilateral. 

 Inner wall of orbit very defective. Sagittal crest moderate in male, feeble in female. 

 Skull relatively broad at frontal constriction. Hard palate truncated, not reaching further 

 back than about the level of the middle of the zygomata, and well in front of the hamulars; 

 the borders of the palate scarcely elevated and its surface almost plane. Vomer with its 

 posterior border completely concealed and reaching the vomerine crest of the superior 

 maxillae. Hamulars strong and curved outwards. Tympanic not swollen or definitely 

 triangular, relatively small and roughened, and with one or two ridges projecting vertically 

 from it ; the bony wall of the external meatus is short ; mastoid massive. Post-canines 



, the last upper is double rooted and is situated distinctly behind the maxillary root 



of the zygoma and the transverse part of the palato-maxillary suture ; between the last 

 and the penultimate tooth is a considerable gap which gives the impression that a tooth 

 had at one time been developed in it, though Mr. Allen states that no evidence has as 

 yet been seen of the presence of a tooth in this gap. Mandible with angle not verv 

 prominent ; subcondyloid process massive, vertically elongated, but not projecting so 

 much inwards as in Otaria jtibata ; lower border of body neither inverted nor everted. 

 The skull originally described by Dr. Gray as Arctocephalus monteriensis is now regarded 

 as a specimen of Steller's Sea Lion. A most interesting account of the habits and 

 characters of this seal has been given by Mr. H. E. Elliott in his work on Alaska already 

 frequently referred to, in which he points out that in this species also the adult male is 

 about twice the weight and bulk of the adult female, and Mr. Allen states that the 



