The brain of the Seal tribe is usually much developed, and writers 

 best acquainted with the habits of the species accord to these animals 

 the possession of a considerable amount of intelligence and sagacity, 

 scarcely inferior to those exhibited by the dog. This favourable opinion 

 has been frequently verified by many interesting examples, while in a 

 state of semi-domestication ; although it is palpable that these 

 faculties, when exercised in their natural element, the full extent of 

 which we can have no means of accurately ascertaining, must neces- 

 sarily excel those which they manifest on shore. 



With the view of freeing from complication the many intricacies 

 which at the present time obscure the consideration of the animals 

 composing this imperfectly understood Order, and to insure to the 

 student a ready, yet comprehensive insight into the systematic dis- 

 position of the species, I commence by rejecting, as comparatively 

 valueless, the highly elaborated Synopsis of Tribes, Genera, and 

 Species, which have been solely based upon the slight variations 

 exhibited in the cranial development ; for such indications in the jpain 

 are unreliable, and their omission, in regard to methodical deter- 

 mination, presents no appreciable obstruction in the way of future 

 research. 



By the material curtailment, which this decision facilitates, of the 

 list of those alleged distinct kinds whose identity rests wholly upon 

 such adventitious qualities, and likewise by uniting under the same 

 genera the animals whose separate positions have been established upon 

 the equally trivial evidence of a shade of colour or of a limited range 

 of habitat, I arrive at a simpler, and, I believe, at a truer estimate of 

 the number of species which constitute the Pinnipedian group. 



The Seals are arranged in this elementary treatise under two heads, — 

 the Eared, and the Earless Seals: the former represented by one 

 famUy, the Otariadse ; and the latter by three, the Trichechidae, 

 Cystophoridse, and PhocidsB. 



SEALS with external Ears. 

 Family I. OTARIAD^.^ 



Incisors 5^, canines ^, molars S, or sis =r 34 or 36.' 

 The four middle upper incisors frequently have double cutting edges ;^ 

 the lower ones are bifurcate ; molars, generally closely approximated, are 



1 oSs, wrhs, the ear. 



'This dental formula is the usual concise mode of descnbmg the number and 

 position of the various teeth. The upper figures refer to the teeth of the upper 

 jaw, and the lower ones to those of the under jaw ; while the hyphen serves to 

 distinguish the right from the left side. 



3 " A cixcumetance hitherto unknown in any other animal," — Cuvieb. 



