Holt and Calderwood — Report on the Rarer Fishes. 493 



it is probably a sexual character. The pelvic rays in the large female C are very 

 slightly elongated. 



Turning to those examples which are undoubtedly referable to A. laterna, E, a 

 female of 13.8 cm., has the fourth, third, and fifth dorsal rays produced in the 

 order named, the longest being nearly a fourth the length of the head. The 

 smaller females of the Irish series show no traces of elongation of the rays. The 

 largest of the males preserved is unfortunately only 9.2 cm. long. None of 

 them have the dorsal rays perceptibly produced. The ends, however, are 

 distinctly filamentous in specimen J. The smaller females, E, IT, L, and M show 

 no traces of differentiation. 



The single North Sea example, iV", a male of 12.4 cm., has the third dorsal I'ay 

 slightly produced. Among the Norwegian fish, 0, a male of 12.2 cm., has the 

 third and second rays slightly elongated, the third ray being rather less than 

 one-third the length of the head. None of the others have the rays at all 

 produced. 



Our series, therefore, incomplete though it is, does show such a difference in 

 the degree of elongation of the fin-rays as might be expected if we were dealing 

 with a single species characterized by the production of the rays in question (to an 

 extent varying according to sex) when a certain size is obtained. 



With regard to the general proportions we find nothing in the Table to indicate 

 a distinction as between A. lophotes and A. laterna. The variation which is 

 indicated in the proportion borne by the length of the head and the greatest 

 height of the body, respectively, to the total length without the caudal fin seems 

 to be chiefly individual, in so far as it is not merely developmental. The 

 specimens agreeing with A. laterna have certainly a lai-ger head, on the whole, 

 than those possessing the characteristics of A. lophotes, but this is what might be 

 expected if the former are merely younger stages of the latter. Individual 

 variations in the height of the body is so well illustrated by comparison of B and 

 D, both typical A, lophotes, that other differences in the whole series cannot be 

 regarded as important. The single North Sea example has actually a higher body 

 than any of the rest, but the want of other material from the same region 

 precludes any profitable speculation as to the existence of local variations in this 

 respect. 



A peculiarity in shape, which does not appear from the proportions given in 

 the Table, is the bluntness of the anterior profile in A. lophotes. The males, 

 however, of this category exhibit this character more strongly than the female, C, 

 while the anterior profile, though rather variable, becomes certainly more obtuse 

 in the A. laterna series as the size increases. 



The proportions of the eye and maxilla presented, perhaps, to some, one of the 

 greatest difficulties in the acceptance of Mr. Cunningham's arguments as to tho 



