20. CALLIOXYMUS. 141 



females, exactly as is the case in Gallinaceous birds. The proof of 

 this is easily established : — 



1. There has never been found a female or a young specimen 

 among the indi\dduals called C. lyra, L., or Gemmeous Dragonet, 



2. A gradual development in the prolongation of the dorsal fin, of 

 the snout, and of the anal papilla, and a gradual change in the 

 colours are observed in the male individuals, and are always found in 

 accordance with the size, that is, with the age, of the individual, 



3. All the females observed belong to the form which is called 

 C. dracunculus, L., or the Sordid Dragonet. 



A difference in the habits of the Gemmeous and the Sordid 

 Dragonet, observed by Mr. Couch, has also been brought forward as 

 a proof of their specific distinctness : — " The Yellow Skulpin (Gem- 

 meous D.) prefers deeper water, whereas the other will often ap- 

 proach the margin of the tide." Such a difference in habit is to 

 be observed in almost all fishes, larger individuaLs not being found 

 in localities where smaller ones abound ; young fishes, besides, are 

 generally more active in their habits than old ones. 



Callioni/miis lyra offers another instance of the great variation to 

 which many species of fishes are subjected by age or sex. In some 

 of them, as in the present species, one or sevei'al organs assume 

 greater proportions Avith age, in othex's the same organs appear much 

 more developed in youth (Xiphias gladius, Stromateus, Platax). In 

 some species this change is confined to one of the sexes only, whilst 

 in others it affects both. 



The following specimens are in- the British Museum Collection : — 



a. Adult male. England. 



h-d. Adult female and half-grown. Mouth of the Thames, Mus. 



Leach. 

 e,f-g. Half-grown males. Brighton, 

 h-i. Adult males, Falmouth, 

 k. Adult male. Pl;yTnouth, Mus, Leach. 



I. Adult male : skin. Plymouth. From Mr. Yarrell's Collection. 

 m. Adult male. Hythe. Presented by H. B. Mackcson, Esq. 

 n. Adult male, Sandgate, Presented by the Bev, G, Smith. 

 o-p. Half-grown males : skins. Biver Tawar, From Mr. Yarrell's 



Collection. 

 q-r. Adult males, Lisbon, Presented by the Bev. B._T. Lowe. 

 s. Half-grown male, Adriatic. Purchased of Mr, Frank. 

 t. Half-grown male. He de France. Mus. Leach. 

 u. Adult female. He de France. Mus. Leach. 

 V, w, ic-y. AdvM males. 

 2-y, Adult males : skins, 



d. Adult female : skin. From Mr, Yarrell's Collection. 

 €. Adult female. From the Haslar Collection, 

 ^. Half-grown male. 

 T). Adult male : skin. 



0, Half-grown male : skin. \ From Gronow's Collection, 

 i. Adult female : skin. 



