126 GRESSIGRADA. 
Group I.—GRESSIGRADA. 
Eared 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 1.—OTARIIDA. 
Bared 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 witha subcylindrical external conch. Testes 
scrotal. 
Dentition.—I. 2, C. 7, M. 2 OF 2 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.—ZALOPHOUS, 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. 
