80 MAMMALIA. 



landing, except for the purpose of basking in the sun, and suckling 

 their young. Their elongated body; their very movable spine, 

 which is provided with muscles that strongly flex it; their narrow 

 pelvis; their short hair, that adheres closely to the skin, all unite to 

 render them good swimmers; and all the details of their anatomy 

 confirm these first indicia. 



We have as yet distinguished two genera only, Phoca and Tri- 

 chechus. 



Phoca, Lin. 

 Seals have sis or four incisors above, four or two below, pointed caninl and 

 grinders to the number of twenty, twenty-two, or twenty-four, all trench- 

 ant or conical, and without any tuberculous part whatever; five toes to all 

 the feet, the anterior ones regularly decreasing in length from the thumb 

 to the little toe, while in the hinder feet the thumb and the little toe are the 

 longest, and the intermediate ones the shortest. The fore-feet are envel- 

 oped in the skin of the body as far as the tarsus, the hinder ones almost to 

 the heel. Between the latter is a short tail. The head of a Seal bears a 

 resemblance to that of a Dog, whose intelligence and soft expressive look 

 it also possesses. It is easily tamed, and soon becomes attached to its 

 keeper, or those who feed it. The tongue is smooth and sloped at the 

 end, the stomach simple, cjecum short, and the intestinal canal long, and 

 tolerably regular. These animals live on fish; always eat in the water, and 

 close their nostrils when they dive by a kind of valve. They remain a 

 long time under water; there is a large venous sinus in the liver, which must 

 assist them in diving by rendering respiration less necessary to the motion 

 of the blood. Their blood is very abundant and very black. 



Phoca, properly so called, or without external ears. 



The true Phocje have pointed incisors; all the toes enjoy a certain de- 

 gree of motion, and are teiininated by pointed nails planted on the edge 

 of the membrane, which unites them. 



They are subdivided, from the number of their incisors. The Caloce- 

 PHAiA, Fr. Cuv. have six above and four below; such is the 



Phoca vitulina, L. (The Common Seal.) From three to five feet in 

 length; of a yellowish grey, more or less shaded and spotted with brown, 

 according to its age; sometimes brownish, with small yellow spots. When 

 very old it becomes whitish. Common on the coast of Europe in great 

 herds. It is also found far to the north; we are even assured that it is this 

 species which inhabits the Caspian sea, and tlie great fresh water lakes of 

 Russia and Siberia, but this assertion does not appear to be founded on 

 an exact comparison. In fact, the European seas contain several Phocae, 

 which have long been confounded, some of which are perhaps mere varie- 

 ties of the others. 



