Chap. XII. 
FISHES. 
9 
°f the dorsal fin. The young males resemble in struc- 
ture and colour the adult females. Throughout the 
genus Callionymus, 13 the male is generally much more 
brightly spotted than the female, and iu several species, 
not only the dorsal, but the anal fin of the male is much 
elongated. 
r The male of the Cottus scorpius , or sea-scorpion, is more 
lender and smaller than the female. There is also a 
gi'eat difference in colour between them. It is difficult, 
us Mr. Lloyd 13 remarks, “for any oue, who has not seen 
‘ this fish during the spawning-season, when its hues are 
' brightest, to conceive the admixture of brilliant colours 
! "’ith which it, in other respects so ill-favoured, is at 
' that time adorned.” Loth sexes of the Labrus inixtus, 
although very different in colour, arc beautiful; the male 
being orange with bright-blue stripes, and the female 
bright-red with some black spots on the back. 
In the very distinct family of the Cyprinodontidse — 
'■"habitants of the fresh waters of foreign lands — the 
Sex es sometimes differ much in various characters. In 
the male of the Mollienesia petenensis the dorsal fin is 
greatly developed and is marked with a row of large, 
round, ocellated, bright-coloured spots ; whilst the same 
tin in the female is smaller, of a different shape, and 
"narked only with irregularly-curved brown spots. In 
the male the basal margin of the anal fin is also a little 
Produced and dark-coloured. In the male of an allied 
torni, the Xiphophorus Hellerii (fig. 29), the inferior 
Margin of the anal fin is developed into a long filament, 
Catalogue of Acanth. Fishes in the British Museum,’ by Dr. 
, 3 nt : he r, 1861, p. 188-151. 
u wr- ame °f Sweden,’ &c., 18G7, p. 460. 
B r vf ttk respect to this and the following species I am indebted to 
(j 1 - Ciinther for information: see also his paper on the Fishes of 
en la, t America, in ‘ Transact. Zooiog. Soe.’ yol. vi. 1868, p. 485. 
