M Y P O T A M U S. 



known even to the most learned in zoology. The 

 name myopotamus, given to the animal by Commerson, 

 is nearly synonymous with hydroatys, the common 

 name of almost all aquatic rodentia except the beavers; 

 and it was understood to have no inconsiderable 

 resemblance to two Australian species lately disco- 

 vered in its external characters generally, and espe- 

 cially in the structure of the feet, which are all five- 

 toed, the fore ones with the toes free, and the hind 

 ones with them webbed. In consequence of this it 

 was considered as belonging to the genus hydromys 

 as then established ; but when its system of dentition 

 came to be examined, it was found to resemble much 

 more the dentition of the beavers, having four cheek 

 teeth in each side of both jaws, as the beavers have, 

 and not two, as in the genus hydromys, though the 

 number of incisive teeth in both are the same, namely, 

 two in each jaw. This different structure of the mouth 

 indicated a different species of food, more difficult of 

 mastication, and approaching to that on which the 

 beaver subsists ; and after this discovery had been 

 made, it was found, upon further examination, that 

 there were great and very characteristic differences 

 between it and those animals of New Holland with 

 which it had at the first been classed. Its body is 

 much less vermiform, that is, slender and flexible, and 

 capable of twining its way among bushes, than the 

 bodies of these. Its claws, also, are much larger, 

 blunter, and not nearly so much arched ; and its tail 

 is less hairy than theirs, and more covered with 

 scales. All those differences indicate not only an 

 animal of very different habits, but an animal whose 

 habits are decidedly more aquatic. The lithe bodies, 

 the crooked claws, and the hairy tails of the Australian 

 animals, afford proofs that they seek for some sort of 

 prey, either animal or vegetable, among the tangled 

 herbage on the margins of the streams, whereas the 

 opposite characters of the same structures, in the 

 South American animal, are equally conclusive evi- 

 dence that the water is the grand theatre of its action. 



most of their time in the water ; and that the differ- 

 ence of temperature of the water indifferent latitudes 

 is very small, compared with that of the earth or the 

 air. Besides, the streams of South America near the 

 Andes (and it is in these, rather than the broad waters 

 of the plains, that the coypou resides) contain a consi- 

 derable portion of snow-water all the year round ; and 

 thus their temperature is low in proportion to the 

 latitude. The existence of this animal in warm lati- 

 tudes may be regarded as a proof of the influence 

 which melting snows can exert upon the waters even 

 of a tropical climate. There is, as we have said. 

 only one species of this curious animal ; and this 

 species we shall now very shortly notice. 



THE COYPOU (Myopotawns coypus.} This ani- 

 mal is among the largest of the rodentia, measuring 

 about one foot nine inches and a half in length, in- 

 dependently of the tail, which is about one foot two 

 inches and a quarter. The legs are rather short, as 

 compared with the size of the animal, being not above 

 four inches and a half in length. The incisive teeth 

 are maroon red on their external surfaces ; the claws 

 are black ; and the ears, which are small and rounded 

 like those of the genus Ht/dromys, have the convex 

 surfaces thickly covered with short hair. The gene- 

 ral colour of the fur on the back is maroon brown, 

 becoming brighter on the flanks, and passing into 

 bright red ; while the tint of the belly is reddish 

 sand-colour. These colours are liable to apparent 

 changes, however, being of a different tint when the 

 animal bristles them up, than when they are laid flat. 

 Each hair is brownish ash at the root, and bright red 

 at the point. The felt, or fine fur which is concealed 

 under the long hairs, is brownish ash, rather deep in 

 the tint on the upper part, but paler on the belly. 

 As is the case in all aquatic mammalia, the hairs on 

 the tail are few, short, and stiff; they are of a reddish 

 sand-colour, and interspersed with scales on the naked 

 parts. The circumference of the mouth, the termi- 

 nation of the muzzle, and the mustachios, which are 



This being ascertained, it became necessary to esta- long and stiff, are white, but the mustachios are in- 

 blish this animal into a new genus, and Corumersori's j terspersed with some black hairs. These animals 

 name has been retained, while the name given by 

 Molina has been Latinised as the specific one. 



At 



present, however, there is not much need for a specific 

 name, because there is no other known species of the 

 genus, nor is it very probable that another will be 

 found ; but the specific name leaves the generic one 

 open in case that such a discovery should be made 

 at any future period. 



This is in some respects a curious animal. The 

 beaver, properly so called, is found only in cold coun- 

 tries ; and so is the sub-genus Fiber, which agrees 

 with the water-rats and field-mice in the structure of 

 its teeth. This animal approaches more nearly to 

 the beaver in dentition, which is the essential cha- 

 racter of an animal, than any of the rodentia even 

 of cold countries ; and yet it is found only in the 

 warm parts of America. It is therefore a sort of 

 anomaly in the animal world ; for it is not a little re- 

 markable to find in the tropical and the polar parts 

 of America two animals resembling each other so 

 nearly in their teeth, and also in the covering of their 

 bodies ; while polar and tropical animals are not only 

 in general very different in the coverings, but that the 

 covering of an animal undergoes a decided change 

 when that animal is transferred from the one of these 

 localities to the other. It must be borne in mind, how- 

 ever, that both the coypou and the beaver spend 



NAT. HIST. VOL. III. 



are, however, affected with albinoism in a good many 

 instances ; and it is worthy of remark that this affec- 

 tiori is so common in some parts of tropical America, 

 that it is not rare among the people of colour. Tin; 

 albinos of the coypou are not, however, entirely 

 white ; for in them the maroon on the back is changed 

 to red and the red on the flanks to a very pale tint 

 of the same. It is possible, however, that these sup- 

 posed albino skins may be merely those of young 

 animals or of females ; although D'Azzara says that 

 the female is very like the male. 



The skins of these animals have for a long time 

 been imported into Europe in very great numbers ; 

 and the soft under-fur has been employed in the 

 manufacture of hats, in exactly the same manner as 

 the under-fur of the beaver. 



The manners of this animal are imperfectly known, 

 nor have its geographical limits been settled with 

 that precision which would be desirable. D'Azzara 

 and Molina are still the authors who have published 

 the best and almost the only accounts of this animal, 

 though, from the researches now going on, we may 

 anticipate that before long we shall be better ac- 

 quainted with this, and with all the other peculiar 

 animals of South America, whose history, could we 

 obtain it fully and satisfactorily from actual observa- 

 tion, would be one of the most interesting chapters 

 U 



