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Show 1890.] SEXUAL C H A R A C T E R S O F A R N O G L O S S U S . 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. M y 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 lyra, in which the two sexes were originally described as distinct species, consists principally Head of Arnoglossus grohmanni, $. 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 entire 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 |