MUSEUM OF COMPARATIVE ZOOLOGY. 21 



Believing that they have a higher than a sub-family value, I adopt 

 for the present the classification elaborated by Dr. Gill in his Pro- 

 drome, which is, it seems to me, the most natural arrangement of the 

 Pinnipedes that has been proposed. Gill's arrangement places the 

 Otariadce between the Phocidce and the Rosmaridce. No serial ar- 

 rangement of these groups can, I think, fully express their relative 

 rank and mutual affinities. The Otariadce are evidently the highest, 

 though they seem intermediate in general features between the earless 

 seals and the walruses. Their affinities, as they appear to me, may 

 be indicated as follows : — 



Otariadce. 

 Rosmaridce. 



Phocidce. 



While the Rosmaridce are lower than the Otariadce, and the Phocidce 

 are still lower than the Rosmaridce, the latter evidently do not con- 

 nect the other two groups. 



The evidence of the superiority of the Otariadce over the Phocidce 

 consists mainly in that modification of their general structure, and es- 

 pecially of the pelvis and posterior extremities, by means of which they 

 have freer use of their limbs, and are able to move on land witli 

 considerable rapidity; the Phocidce, on the other hand, move with 

 great difficulty when out of the water. But the higher rank of the 

 former is also indicated by their semi-terrestrial habits, the scrotal po- 

 sition of the testes, and in the nearer approach in general features 

 to the terrestrial Carnivores, especially in the more posterior position 

 of the acetabula. Most of these modifications are, however, nearly 

 equally shared by the Rosmaridce, indicating likewise that their true 

 station is above that of the majority of the Phocidce. 



Primary Subdivisions. — The members of the Otariadce form among 

 themselves a closely connected group, as well as a well-defined one. 

 But in general form, in size, in color and in the character of the pelage, 

 two tolerably distinct divisions of the Otariadce may be recognized, 

 which in a general way correspond with the sea bears* and sea lions 

 of seamen, and the fur seals and hair seals of commerce. F. Cu- 

 vierj was the first naturalist who recognized these divisions, he regard- 



* The term sea bear, however, has been sometimes applied indiscriminately to 



fur and hair seals, and even to the same animal by the same person, as in the case of 

 the first living specimen of Otarla jabata, exhibited in England. 

 t Mem. du Mus., Tome XI, p. 205 tt seq., 1824. 



