AKT. 15 ANATOMY OF THE EARED AND EARLESS SEALS HOWELL 5 



siibadult, unsexed, and bears the number 6297, from Cumberland 

 Gulf, April, 1878, collected by L. Kumlien. As representing the 

 Otariidae, the National Museum secured through the interest of the 

 Johns Hopkins Medical School an embalmed juvenal female 

 Zaloplxus calif ormmius that died September 6, 1925, after being at 

 the Baltimore Zoological Park for only a short time. Sundry an- 

 atomical observations were also made upon a large adult female of 

 this species that died at the National Zoological Park during June, 

 1927. For osteological comparison the most suitable skeleton avail- 

 able was that of a subadult male, disarticulated. No. 200847 of the 

 National collection, that died at the National Zoological Park De- 

 cember 19, 1915. There was also at hand some less satisfactory 

 skeletal material of this same species, some of Phoca, mounted skele- 

 tons of both families, and an extensive collection of skulls. It 

 should be understood that in the following pages the above speci- 

 mens, upon which the present study is primarily based, are referred 

 to not by number, but by such terms of designation as " the otariid " 

 (the embalmed specimen for the muscles, and the skeleton for osteo- 

 logical details), or "my phocid." My study of the prepared speci- 

 mens has been supplemented by observation, as often as possible, of 

 both wild and captive specimens of Zcdo'p'hus and Phoca (of the 

 vituUna and richardii sorts). 



EXTERNAL FEATURES 



The length from nose to tip of tail was 978 in the Zalophus and 

 1,019 mm. in the Phoca^ so these embalmed specimens were as nearly 

 comparable in size as one could reasonably wish. The length of tail 

 in the former was 60, and in the latter 72 mm., and the circumference 

 of the thorax respectively 430 and 780 mm. The sea lion was exces- 

 sively emaciated and not only was there no fat but most of the 

 muscles where somewhat shrunken. The seal, on the contrary, was 

 \ery fat, this being, tender and free from fibrous tissue. Over the 

 shoulder it was about 30 mm. in thickness, thinning toward the head, 

 caudad in the region of the hind flippers, and upon the forelimbs. 

 In a state of nature females and immature males of Zalophus are 

 usually sleek and of slender appearance, although captive specimens 

 and old males may become fat and logy; but it is normal for at 

 least most of the Phocidae to have an extensive blubber layer. All 

 pinnipeds have a form that is markedly " stream-line " but whicli 

 animal is the more eflicient in this respect we do not know. Both 

 are covered with short stiff hairs, the pelage of the phocid being the 

 thicker. 



In the otariid the mystacial pad had a width of 40 mm. and ap- 

 peared rather narrow. The vibrissae were directed chiefly caudad 



