REPORT ON THE SEALS. 



77 



average length of ten old male skulls is 375 mm., their breadth 221 mm. ; whilst the 

 mean length of two old female skulls is 296 mm., and their mean breadth 157 mm. In 

 the examination, therefore, of the adult skulls of the Sea Lions, both northern and 

 southern, differences in size are of no value as indicative of specific characters, but are 

 only of sexual importance. 



Eumetopias californianus (Lesson). Californian Sea Lion. 



Otaria cdliforniana, Lesson, Diet. Class d'Hist. Nat., xiii. p. 420, 1828. 



„ GiJIespii, M'Bain, Proe. Roy. Phys. Soc. Edin., vol. i. p. 422, 1858. 

 Aretocephalus gilliespii, Gray, Brit. Mus. Catal., p. 55, 1866 {error e). 

 Zalophus gillespii, Gill, Proc. Essex Inst., vol. v. p. 13, 1866. 



The late Dr. James M'Bain, E.N., of Edinburgh, was the first naturalist to describe 

 the skull of this animal 1 from a specimen obtained from the Gulf of California, which 

 was given to him by his friend Dr. Gillespie. I purchased this skull after Dr. M'Bain's 

 death for the Anatomical Museum of the University of Edinburgh. This animal is 

 generally recognised as distinct both from its southern neighbour, Otaria juhata, and 

 from the northern or Steller's Sea Lion, though whether a special genus Zalophus should 

 be established for it, or it should be regarded as only a distinct species of Otaria, or of 

 Eumetopias, is stdl a moot point amongst zoologists. Although Dr. M'Bain's description 

 embraces many of the characters of the cranium, and particularly the prominent sagittal 

 crest on the vertex of the skull, yet I may refer to several additional points and 

 measurements. 



Table IX. — Skull of Eumetopias californianus. 



1 Proc. Roy. Phys. Soc. Edin., vol. i. p. 422, 1858. 



