204 BRITISH MAMMALS 



GENUS: HALICHCERUS 

 Halichcerus grypus. THE GRAY SEAL 



This is a larger seal than the other members of the Phocine 

 sub-family, and it is the only other species besides the common 

 seal which can be with any emphasis regarded as a British 

 mammal. It is not very clear that the differences between the 

 Gray Seal and the rest of the Phocinae are of generic importance. 

 The distinctions are based on the configuration of the premolar 

 and molar teeth. These, instead of being provided with two or 

 more cusps in addition to the central cone, are much simplified 

 and reduced to conical compressed crowns. Occasionally the 

 molars in the lower jaw have small hinder accessory cusps. 

 Moreover, three at least of the premolars in each jaw are only 

 single-rooted, and not double. It is, of course, an instance of 

 degeneration and simplification of structure, the molar teeth in 

 the gray seal becoming like those in the whales simple pointed 

 crowns like the canines and incisors. 



The length of the adult male of the gray seal may be nearly 

 as much as 1 1 ft., though the measurement of the females 

 scarcely reaches 7 ft. 6 in. The average male is perhaps be- 

 tween 9 ft. and i oft. in length. The colour varies a great deal 

 according to age and individuals. The young is at first a lemon- 

 white in tint, and this woolly coat is retained for perhaps as long 

 as six weeks. The young gray seal then becomes in the main 

 yellowish-white on the under surface, and is heavily marked with 

 quite a dark blackish-brown above. In fact, its coloration is 

 almost black and white, the black being distributed in splotches 

 and spots and streaks on a white ground. The top of the head 

 and the region round the ear, the ridge of the nose and the 

 upper part of the muzzle, are blackish, with a white spot round 

 the eye. The flippers are marked with black spots. Some of 

 the white parts in the young seal are tinged with yellow. 

 Gradually as age increases the white or yellow parts of the fur 

 darken into brownish-gray, while the black marks fade into sooty 

 brown, until at last the whole aspect of the creature is grayish- 



