480 ZOOLOGY. 



Order 7. Carnivora. 

 Group 1. Pinnipedia. 



The seals, whicli constitute this group, were for a long time not distin- 

 guished from the herbivorous Cetacea, the name of sea-cow, now restricted 

 to Manati, being indifterently applied to them, with those of sea-calf, sea- 

 dog, sea-bear, sea-lion, &c. Seals, as already remarked, are also among 

 those curious animals which have given rise to the stories of the mermaids 

 of our forefathers, their head generally bearing some resemblance to that of 

 a dog, whose intelligence (we are told) and soft expressive look they also 

 possess. Some species have very inconspicuous ears, and others have 

 merely an auditory aperture ; their jaws are furnished with strong teeth, 

 consisting of incisors, canines, and molars, all well adapted for seizing, hold- 

 ing, and crushing the scaly and slippery prey upon which they feed. The 

 tongue is smooth, and slightly notched at the end ; the feet are formed for 

 swimming ; the front pair is enveloped in the skin of the body as far as the 

 tarsus, and the hinder pair, which is flattened and directed backwards, is 

 enveloped almost to the heel. All the feet have five toes, the anterior ones 

 regularly decreasing in length from the thumb to the little toe ; while in the 

 hinder feet the thumb and the last toe are the longest, and the intermediate 

 ones the shortest. The tail is short, and when the animal is out of the 

 water, is generally concealed by the hind legs pressing close to it. When 

 they dive, they close their nostrils by a kind of valve ; and the large venous 

 sinus in the liver must assist them in diving, by rendering respiration less 

 necessary to the circulation of the blood, which in them is very abundant 

 and very dark colored. 



These animals pass the greater portion of their time in the water, never 

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

 young. They are excellent swimmers, having an elongated body ; a very 

 movable dorsal spine provided with muscles that strongly flex it ; a narrow 

 pelvis ; short hairs that adhere closely to the skin. 



The Pinnipedia form but one family, that of Phocida^, since we have 

 removed the walruses from this group. 



Fam. Phocid^, or the seals, have six or four incisors above, four or 

 two below, pointed canines, and grinders from twenty to twenty-four, all 

 trenchant or conical, and without any tuberculous part whatever ; five toes 

 to all the feet. 



The genus Phoca includes the species deprived of external ears, provided 

 with pointed incisors ; all their toes enjoy a certain degree of motion, 

 and are terminated by pointed nails, planted at the edge of the membrane 

 which unites them. When the number of incisors is six above and four 

 below, we have then the sub-genus Calocephala, of which the common seal, 

 Phoca vitulina {pi. 114, fig. 2), is an example. It is from three to five feet 

 in length ; found on the coast of Europe in great herds. When the incisors 

 are four above and four below, and the molars deeply notched into three 

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