126 GRESSIGRADA. 



Group I. GRESSIGRADA. 



Bared Seals ; Walruses. 



Hind limbs capable of being turned forwards, and used in 

 terrestrial locomotion. Neck lengthened. Anterior feet nearly 

 as large as the posterior, their digits rapidly decreasing in length 

 from the first to the fifth, without distinct claws, and with a 

 broad cartilaginous border extending beyond the digits. Only 

 the three middle digits of the hind feet clawed, and all terminating 

 jn long narrow cartilaginous flaps. 



Family I. OTARIID^. 



Eared Seals. 



Fore limbs placed far back and comparatively free ; palms and 

 soles and the greater part of the upper digital surface hairless. 

 Scapula large. Ears with a subcylindrical external conch. Testes 

 scrotal. 



Dentition. I. f, C, \, M. | or | x 2 = 34 or 36. 



Note. The Group to which this Family belongs are gregarious 

 and polygamous, and the males greatly exceed the females in 

 size. During the breeding season they resort in large numbers 

 to favorite breeding grounds, technically known to sealers as 

 "rookeries," where they leave the water and pass some weeks on 

 land, often at a considerable distance from the shore ; at this 

 period they rarely enter the water and consequently do not feed ; 

 the males especially, on their return to what must be considered 

 their natural element, are greatly emaciated. 



Genus I. ZALOPHCJS, Gill (1866). 



Molars , large, closely approximated, the last under the hinder 

 edge of the zygomatic process of the maxillary. Muzzle narrow. 

 Hinder edge of the palatine bones deeply concave. Sagittal crest, 

 in very old males, forming a remarkably high, thin, bony plate, 

 unparalleled in its great development in any other genus in the 

 Family. 



1. ZALOPHUS LOBATUS, Gray, sp. (1828). 

 Australian Sea Lion. 



In the adult the face, front and sides of the neck, all the under 

 surface, sides, and back dark- or blackish-brown, passing into 

 dark slaty-gray on the extremities of the limbs ; the hinder half 

 of the crown, the nape, and back of the neck rich deep fawn 

 color ; eyes black. 



