PEOGRESS OF ICHTHYOLOG-Y. 427 



division. . He could not have done better, says Cuvier, 1 if his object 

 had been to turn into ridicule all artificial methods, and to show tc 

 what absurd combinations they may lead. 



Cuvier himself, who always pursued natural systems with a singularly 

 wise and sagacious consistency, attempted to improve the ichthyolo- 

 gical arrangements which had been proposed before him. In his 

 Reyne Animal, published in 1817, he attempts the problem of arranging 

 this class ; and the views suggested to him, both by his successes and 

 his failures, are so instructive and philosophical, that I cannot illus- 

 trate the subject better than by citing some of them. 



" The class of fishes," he says, 14 " is, of all, that which offers the 

 greatest difficulties, when we wish to subdivide it into orders, accord- 

 ing to fixed and obvious characters. After many trials, I have deter- 

 mined on the following distribution, which in some instances is wanting 

 in precision, bnt which possesses the advantage of keeping the natural 

 families entire. 



" Fish form two distinct series ; that of chondropteryyians or carti- 

 laginous fish, and that offish properly so called. 



" The first of these series has for its character, that the palatine 

 bones replace, in it, the bones of the upper jaw : moreover the whole 

 of its structure has evident analogies, which we shall explain. 



" It divides itself into three ORDERS : 



" The CTCLOSTOMES, in which the jaws are soldered (soudees) into 

 an immovable ring, and the bronchise are open in numerous holes. 



" The SELACIANS, which have the bronchiae like the preceding, but 

 not the jaws. 



"The STURONIANS, in which the bronchia? are open as usual by a 

 slit furnished with an operculum. 



" The second series, or that of ordinary fishes, offers me, in the first 

 place, a primary division, into those of which the maxillary bone and 

 the palatine arch are dovetailed (engrenes) to the skull. Of these I 

 make an order of PECTOGNATHS, divided into two families ; the gymno- 

 donts and the scleroderms. 



" After these I have the fishes with complete jaws, but with bron- 

 chia? which, instead of having the form of combs, as in all the others, 

 have the form^of a series of little tufts (houppes). Of these I again 

 form an order, which I call LOPHOBRAXCHS, which only includes one 

 family. 



a p. 108. " Rigne Animal, vol. ii. p. 110. 



