8 CLASSIFICATION OF MONOCARDIAN AXI3IALS. 



(7.) The relations -which these animals bear to 

 quadrupeds and birds may next be glanced at. Com- 

 mencing with fish^ we find that the dolphins^ porpoises, 

 and the other aquatic Mammalia without feet^ were 

 always regarded by the ancients as true fishes ; and even 

 Artedi, the great renovator of ichthyology in the eighteenth' 

 century^ viewed them in this hght. The passage, there- 

 fore, from quadrupeds to fish is absolutely perfect ; and 

 the affinity of the sharks to the dolphins shows that this 

 passage takes place among the cartilaginous fishes ; of 

 which Cavier remarks, that they also evince an affinity 

 to the ReptlUa, Fishes are remarkable, among their 

 other peculiarities, for being destitute of feet ; these 

 members being replaced or represented by two sets of 

 fins ; the pectorals representing the anterior feet of four- 

 footed beasts, while the ventral fins equally represent' 

 the hinder feet. But among the least perfect or aberrant 

 groups of this class we find these fins so constructed, 

 that they are placed on a jointed peduncle, so that they 

 have nearly as strong a resemblance to the foot of a frog, 

 or that of a s-^vimraing bird, as to a fin {fig. 1. a) ; nor 

 is this in appearance only ; for it has been frequently 

 asserted by those who have seen the Indian Chironectes, 

 or frog-fishes, ahve, that those singular animals crawl 

 about by means of these foot-fins, and that they are 

 so far amphibious as to live comfortably two or three days 

 out of water. Their thick grotesque shape, naked and 

 tuberculated body, and their whole general aspect, give 

 them, in short, much more the appearance of frogs than 

 of fishes, — an assertion to which the most unscientific 

 of our readers will acquiesce upon looking to the annexed 

 cut of the 31althe nasuta Cuv. {^fig. 1.), accurately drawn 

 from a specimen we procured on the Brazilian coasts: (a is 

 the pectoral fin.) Xor is this a solitary affinity between 

 the amphibians and the fishes ; the whole of Cuvier's 

 genus Chironectes, wh-ich is evidently a natural family, 

 abounds with similarly formed animals, where the gene- 

 ral aspect and characters of true fishes are so much 

 changed as to assume the appearance of frogs. Quitting 



