1890.] 



SEXUAL CHARACTERS OF ARNOGLOSSUS. 



545 



rated from the second but connected posteriorly with the membrane 

 of the dorsal fin. The 4th ray is slightly longer than the 5th ; 

 from the 5th backwards the rays increase gradually in height as 

 usual. The specimen is also higher in proportion to its length than 

 those described in Dr. Giinther's paper, the greatest height being 

 contained 2| times in the total length including the caudal fin. 



My specimen is a male, and there can be no doubt that those 

 characters I have described in which it differs from previously known 

 specimens of Arnoglossus grohmanni are secondary sexual characters 

 peculiar to the male sex. Thus an interesting sexual dimorphism 

 occurs in both these species of Arnoglossus. It is worth noting 

 that the sexual dimorphism of Callionymus h/ra, in which the two 

 sexes were originally described as distinct species, consists principally 



Head of Arnoglossus grohmanni, (f . 



in a difference of the same kind as that in the genus Arnoglossus, 

 namely a great elongation in the male of the anterior dorsal fin- 

 rays. 



The specimen here described, when first found in a pan of trawled 

 material, was dead but perfectly fresh. Nearly all the scales except 

 those of the lateral line were wanting, but the skin was nearly en- 

 tire and showed the colour and markings distinctly. The general 

 colour was rather dark and sombre, the markings consisted of black 

 and orange blotches and streaks. The black blotches were arranged 

 on the upper side as in the common Sole, namely in three principal 

 longitudinal rows, one along the lateral line and one along each 



