ANALOGIES. — CARTILAGINES TO BIRDS. 157 



especially Polyodon and Chimmra, of which nothing 

 that we have yet said relates to the enormous flattened 

 snout of the first, or the lobe-shaped crest of the last. 

 We shall, therefore, now exhibit the analogies of the 

 cartilaginous types in a new light, by bringing them 

 into contact with the primary orders of birds. 



Families of the • Analogies. Orders of Birds. 



Choxdropteryges. ° 



Squalidce. Pre-eminently rapacious. Raptores. 



BaitLs. Typical of their respective circles. Incessores. 



iv^~,~~~j^ S Males with crests or frontal ap- 7 r.„„ di ,„ 



Oumairida!. J pe ndages. J Rasores 



Sturionidce. Mouth very small. Grallatores. 



Polyodonidce. Snout or bill excessively broad. Natatores. 



(138.) The two first set of analogies are so obvious, 

 that every naturalist will at once perceive them. It 

 follows, indeed, as a necessary consequence, that if the 

 sharks represent the beasts of prey, they also represent 

 the rapacious order of birds ; and that if the Raidce are 

 typical of birds, they must bear the same relation to 

 that group which is the most perfect among birds. 

 The rasorial type of form, already so much enlarged 

 upon in former volumes, is eminently distinguished 

 from all others by the heads of one or both sexes being 

 ornamented or defended by unusual appendages, which 

 among quadrupeds take the shape of horns, and in 

 birds that of crests. The Chimcera borealis exhibits an 

 appendage perfectly analogous to this, in the singular 

 fleshy caruncle or lobe which surmounts its snout, 

 the end of which is beset with numerous short prickles ; 

 while the tail, as in all rasorial types of the Vej'tebrata, 

 is highly and singularly developed. Thus we have, 

 among fishes, a structure perfectly analogous to the 

 rasorial order of birds, and to the ruminating order of 

 quadrupeds ; and as the types of the rasorial birds (the 

 family of peacocks) are among the most splendid 

 coloured of the class, so Chimcera is the only group 

 among the cartilaginous fishes whose colours have any 

 degree of brilliancy. The difficulties attending the 



