CLASSIFICATION OF DEVONIAN FISHES. 



17 



but the characters of the spinal column, of the median fins, of the 

 scales, and of the tail, are so exactly those exhibited by the Undina 

 of Miinster (of which sundry complete specimens exist), that the 

 very close affinity of the two genera is beyond doubt. Agassiz, in 

 fact, proposes fco distinguish them only by their teeth ; Cmlacanthus 

 having, in his opinion, conical and recurved, while Undina has 

 flat, pavement-like and tuberculated teeth. That Miinster was 

 correct in assigning such teeth to Undina I have satisfied myself 

 by the examination of a well-preserved specimen of U. Kd'hleri in 

 Lord Enniskillen's collection ; but what evidence is there that 

 Codacanthus has a difierent dentition ? Agassiz was led to believe 

 that the teeth of the latter genus are conical, by the fact that the 

 specimen of a fish named by him G. Munstevi has such teeth. I am 

 again indebted to the Earl of Enniskillen, of whose collection this 

 specimen forms a part, for the opportunity of verifying the state- 

 ment ; but I must at the same time express my entire concurrence 

 in the opinion previously expressed to me by Sir Philip Egerton, 

 that the so-called " Ccdacanthus " Micnsteri is not a Coelacanthus 

 at all. 



For, as I have stated above, there can be no doubt that Coela- 

 canthus (G. granulatus being the typical species) was, in all the 

 great features of its organization, similar to Undina ; so that, con- 

 trariwise, any fish which diff'ers in essentials very widely from 

 Undina can be no Goelacanthus. 



Restoration of Undina. (Partly after Mimster, partly from Lord Ennislvillen's 

 specimen. Below the head are the eontom's of the jugular plates.) 



10 B 2 



