These inferences, derived comparatively from only a few generalities, 

 may be considered as too theoretical, but palseontologists have already 

 revealed to us the interesting forms — some unfortunately imperfect — of 

 the extinct Deinotherium, the Halitherium, and the Zeuglodon, whose 

 remains have, by their intermediate character, materially aided to 

 substantiate the alliance between the finned Mammals. 



There still exists, however, a wide and indefinite interval which 

 separates the three orders, and which will have to be filled up by the 

 further discoveries of fossil relics before any satisfactory linear 

 arrangement can be assured. 



PINNIPEDIA. 



Order 7. PINNIPEDIA,^ 



Amphibia* of Cuvier, Otaries,' "Walrus,* Seals." 

 The front Umbs of all the animals which compose this order are 

 powerful, short, nearly hidden within the skin of the body ; the paws, 

 however, advance, are fin-like, and provided with five long fingers, which 

 diverge from each other, and are completely embedded in the sur- 

 rounding membrane : these fingers, in general, diminish in size from 

 what we may call the thumb to the little finger. 



The fore-limbs are used for swimming purposes, for seizing the 

 prey, for assisting in movements on land and for ascending rocks or 

 blocks of ice. 



The hiad limbs are even more powerful than the front ones, and 

 when at rest are in some species directed forwards, similar in position 

 to those of terrestrial mammals ; in others backwards, in a line with 



^ Pinna, a fin ; and pes, a foot. 



^Aii<j>iPios (aii<j>i and Pi6s), capable of living on land and in water. I may remark 

 tliat the term ampHbious, when applied to these animals, is incorrect, for not possess- 

 ing gills they cannot breathe under water, but must come to the surface to respire 

 the atmospheric air, as other mammals do. Existing, however, on fish and other 

 marine prey, they possess, on extraordinary occEisions, the essential attribute of 

 only breathing once in twenty minutes, whereas many land animals are compelled 

 to do so twenty times in the minute. 



' 05j, wrhs, the ear. 



* From the Q-erman " wall," as in wallfiseh, a whale, and " roti " a horse. 



"From the Saxon "seal," "lele," "syU." 



