100 MAMMALIA. 



The Ursal (Ph. ursina, Gm. [Arctocepftahis ur/tini(s, F. Cuv. fig. 40.]— Eight feet long, no mane, varying from 

 brown to whitish. From the north of the Pacific Ocean. 



The Mouse (Trichecus, Lin.) — 



Resembles the Seals in the general form of its body and limbs, but differs considerably from them in 

 the head and teeth. The lower jaw has neither incisors nor canines, and is tompressed anteriorly to 

 pass between two enormous canines or tusks which issue from the upper one, and w : hich are directed 

 downwards, attaining sometimes a length of two feet, with proportionate thickness. The magnitude 

 of the sockets requisite for holding such enormous canines raises up the whole front of the upper jaw, 

 so as to form a thick bulging muzzle, the nostrils opening upwards, instead of being terminal. The 

 molars are all short cylinders, obliquely truncated. There are four [or five] on each side above and 

 below ; but at a certain age, two of the upper ones fall out. Between the canines are two incisors 

 similar to the molars, which the majority of observers have overlooked, as they are not fixed in the 

 intermaxillary bones ; and between these again, in young individuals, are two pointed and 

 small ones. 



The stomach and intestines of the Morse are nearly similar to those of the Seals : and it appears 

 that they subsist on fuci as well as on animal substances. 



One species only has been ascertained, the Morse or Walrus (7V. rosmarus, L.) ; an inhabitant of all parts of the 

 Arctic seas, exceeding the largest Bull in bulk ; it attains a length of twenty feet, and is covered with short yel- 

 lowish hair. This animal is much sought for on account of its oil and tusks ; the ivory of which, though coarse- 

 grained, is employed in the arts. The skin makes excellent coach-braces. [A strange assertion originated with 

 Sir E. Home, that the feet of the Morse possess suckers, by which it is enabled to ascend perpendicular ice-bergs. 

 There is no foundation for this statement. 



It is difficult to intercalate the Amphibia in the series of Carnivora, and to determine to 

 what extent their peculiarities should be regarded as adaptive modifications, based on the 

 rudimental structure of the whole order. 



At the head of the Carnivora we prefer to place the Dogs or Canidm, followed by the 

 ViverridcB and Felidce .- the Seals or Phocidce might, we conceive, next range with less impro- 

 priety than elsewhere : and after them the Mustelidm, and Ursidcej then, finally, the Insectivora, 

 which the author ranks as equivalent to all the foregoing. The Cheiroptera, or Bats, we 

 deem to be subordinate rather to the preceding order. 



Remains of nearly all the principal genera and some additional ones have been found, more 

 or less abundantly, in the tertiary strata, or deposits overlying the chalk, but not in beds of 

 anterior formation.] 



THE FOURTH ORDER OF MAMMALIANS,— 



MARSUPIATA,— 



(Or that of the Pouched Animals,) — 



With which we formerly terminated the Carnaria, as a fourth family of that great ordinal 

 division, presents so many singularities in the economy of its members, that we are induced to 

 separate and elevate it to its present position ; the more particularly, as we observe in it a 

 sort of representation of three very different orders. 



The first of all their peculiarities is the premature production of their young, which are 

 born in a state of developement scarcely comparable to that of an ordinary foetus a few days 

 after conception. Incapable of motion, and barely exhib ; +ing tb* rudiments of limbs and 



