knowledge of the Crenilahri. 443 



about equal numbers caught by lads, fishing from the rocks, who 

 provided me with them. 



This examination proved to my satisfaction that the C. tinea 

 and C. Cornuhicus are not distinct. The colour was as commonly 

 described, in so far that the smaller specimens,* up to the length of 

 six inches, — but not all under this size, — had on the body at the 

 base of the caudal fin the black spot of C. Cornubicus, and the 

 larger (C. tinea) wanted it; also, in the former being generally 

 rather less brilliant in colour. Some specimens of an intermediate 

 size, however, had the above-named spot of an obscure brown, sug- 

 gesting, that this spot, originally black, may change gradually to 

 this colour, and afterwards become obliterated, — an effect analogous 

 to which, but to a much greater extent, takes place, according to 

 Agassiz, in certain species of the Salmonidce, The dorsal fin was 

 similar in all, the spinous portion being marked alternately with 

 longitudinal lines of green and red, and the soft portion red, with 

 roundish green spots. In no other marking or distribution of co- 

 lours was there any difference between them. 



In not one of the many characters which come under the head of 

 '•form' was there any difference ; the proportion of depth to length, 

 denticulations of pre-opercle and teeth,-]- being similar in both. In 

 these characters Mr Jenyns considers the C. tinea and C. Cornu- 

 bieus differ, (Man. Brit. Vert. p. 398,) and from his great accuracy 

 there cannot be a doubt that they did so in the specimens he exa- 

 mined ; but it was, I presume, merely individual, as the differential 

 characters he has assigned to each have occurred to me in the other. 



Dr Fleming has brought these species together, (Brit. Anim. p. 

 208 ;) but we are not informed whether it was their general simi- 

 larity, or an actual examination of specimens that led him to this 

 conclusion. 



Mr Couch remarks of C. tinea and C. Cornubieus, (Mag. Nat. 

 Hist. Vol. V. p. 742,) that they differ in size, shape, colour, and ha- 

 bits. The three first differences have been already dwelt upon; 

 but as to habits, I have only circumstantial evidence of their simi- 



* In the collection of R. Ball, Esq. of Dublin, there are smaller specimens 

 than any obtained at Bangor. Ten of these which I examined, and of which 

 several were about 1 § inch long, had the black spot conspicuous. The largest 

 individual I have seen vdth this marking is 8| inches in length. It was procur- 

 ed on the northern coast of Ireland in the course of the Ordnance Survey. 



f In two Bangor specimens of C. Cornubicus there are fourteen teeth in the 

 lower jaw, a greater number than which is not possessed by any C. tinea I 

 examined with them. The second row of teeth in the upper jaw is most appa- 

 rent in the larger individuals, or, in other words, in C> tinea. 



