SEALS. 173 



singularly flexible ; the head is round, with a large full 

 fleshy muzzle, furnished with long stiff whiskers ; the 

 nostrils are valvular, and capable of being closed at will ; 

 the eyes are large and dark, with a mild intelligent ex- 

 pression, and are adapted for subaquatic vision. The 

 external ears are either wanting or very small, and the 

 auditory orifice is valvular ; the tongue is almost smooth, 

 and is abrupt and indented at its tip ; the brain is large, 

 the lungs voluminous, the stomach capacious. 



The internal arrangement of the venous system is very 

 remarkable, and adapted so as to effect a sort of reservoir 

 for the blood, which naturally accumulates in it when 

 the circulation is impeded during the suspension of 

 breathing, as is perpetually the case as the animals are 

 pursuing their prey beneath the surface of the water. 

 Between the skin, which is very tough, and the muscles, 

 there intervenes a fibrous loose elastic tissue of a dark 

 red tint ; indeed the muscles are dark, and the blood of 

 a blacker hue than in most mammalia. From the ante- 

 rior part of the breastbone (sternum) a long cartilaginous 

 continuation projects forwards for the more extensive 

 attachment of the voluminous muscles acting upon the 

 anterior paddles. The arteries of the limbs are plexi- 

 form, as we have described them in the volume of the 

 Monkeys. 



The varying forms of the skull in the Phocidae will be 

 easily appreciated by reference to our pictorial speci- 

 mens. With respect to the teeth, we may describe them 

 as prehensile ; they are not formed for grinding, but for 

 seizing the slippery prey and dividing its flesh into large 

 portions. Their number is very different in the different 

 species, nor less so are the minor details of their struc- 

 ture. The incisors are six or four above, and four or 

 two below ; the canines are large and strong ; the molars 

 are either simply conical or furnished with cutting edges, 

 and more or less deeply notched with a large central 

 point. Without entering into any disquisition respecting 

 the genera into which the seals are divided, and their 

 arrangement — a point of the less importance, as our 

 know ledge of the group is at present confessedly imper- 



VOL,. III. I 



