58 ANGLING. 



the caudal fin, 71. All these vertical fins vary 

 in different tribes, either in number or dimensions, 

 or the nature of the rays by which they are sup- 

 ported, and which are sometimes spiny, sometimes 

 branched, and composed of numerous articulations. 

 We ought to have observed that even the double 

 fins, or those disposed in pairs, also vary both in 

 size, number, and structure ; and that one or even 

 both pairs are occasionally wanting, as in eels, 

 which have no ventral fins, and mureme, which 

 have neither ventral nor pectoral fins. Indeed, the 

 Apterichti, poor things, have no fins at all. 



It is from a consideration of the structure, or 

 rather of the texture and consistence of these rays, 

 that the titles of two of the principal primary 

 groups in Ichthyology have been derived. Those 

 named Malacopterygiam have all the rays of the 

 fins articulated, and of a softer structure ; while 

 the Acanthopterygians are characterised by having 

 at least a portion of their rays hard, simple, and 

 spinous. These great divisions apply solely to the 

 osseous or bony fishes. We have already men- 

 tioned that the cartilaginous kinds are distinguished 

 by the title of Chondropterygians, which two lesser 

 groups, in some respects intermediate between these 

 and the preceding, fall under the orders Lopho- 

 brancMi and Plectognathi of Baron Cuvier. 



The skeleton of the Chondropterygians, such as 

 sharks and rays, is composed of pieces consisting of 

 no fibrous tissue characteristic of bone. The in- 

 terior continues in a cartilaginous state, and the sur- 

 face alone becomes indurated by the accumulation 



