ALLEN : MAMMALIA : OTARIID/E. 109 



now so well known that a detailed description is unnecessary. It varies 

 greatly in the two sexes, the male skull being much larger than that of 

 the female, with an excessive development of the processes and crests, as 

 age advances. The average dimensions of old male skulls from the 

 Straits of Magellan are: Total length 350 mm., ranging in a series of 8 

 old skulls from 325 to 372 ; zygomatic breadth 223, ranging from 210 to 

 237. Four old female skulls give an average total length of 260 (252 to 

 277), and a zygomatic breadth of 143 (140 to 146).' 



Dr. James Murie- and Dr. William Turner ^ have made known the 

 anatomy of this species in great detail, their work being based on Falk- 

 land Island specimens. 



The Southern Sea Lion bears a strong general similarity externally to 

 the Northern Sea Lion, which it resembles in color and proportions, but, 

 judging from the skulls, it is about one eighth smaller. In cranial char- 

 acters the two animals are remarkably distinct for members of the same 

 family, not only in dental formula but in the formation of the bony palate. 

 But they appear to agree as closely in habits as in external appearance, 

 both being polygamous, and resorting to particular islands or coasts at a 

 definite season of the year to bring forth their young. 



Geographical Distribution. — The Sea Lions of the coasts and islands 

 of southern South America are commonly believed to be referable to a 

 single species, of rather wide distribution. It formerly occurred in great 

 abundance at the Galapagos Islands, and is still found there in small 

 numbers"; also along the coasts of Peru and Chili to Cape Horn, resort- 

 ing especially to some of the islands of this part of the South American 

 coast. It also frequented the eastern coast of Patagonia, and still ranges 

 north to Lobos Island, off the mouth of the Rio de la Plata, and formerly 

 north to the coast of Brazil, off Sta. Catharinal It was formerly numer- 



' Cf. Allen, N. Am. Pinnipeds, pp. 226 (footnote), 246, 247; Murie, Trans. Z06I. Soc. Lon- 

 don, i86g, p. 105. 



' Researches on the Anatomy of the Pinnipedia. Part H. Descriptive Anatomy of the Sea 

 Lion {Otaria jubata). By James Murie, M.D.. F.L.S., F.G.S., etc. Trans. Zool. Soc. London, 

 Vol. VII, pt. viii, Jan., 1872, pp. 527-596, pll. Ixvii-lxxiii ; Vol. VIII, pt. ix, June, 1874, pp. 

 501-582, pll. Ixxv-l.xxxii. 



^Report on the Seals collected during the Voyage of H. M. S. Challenger in the years 1873- 

 76. Zool. Chall. E.xp., pt. Ixviii, 1887, pp. 1-138, pll. i-x. Appendix to the Report on the 

 Seals. The Myology of the Pinnipedia. By Wm. C. Strettell Miller. Ibid., pp. 139-234. 



* Heller, Proc. California Acad. Sci. (3), Zool., XII, 1904, 244. 



''Hensel, Abhandl. K. Akad. Wissen. zu Berlin, 1872 (1873), 91. 



