150 



FOUR-HORNED ASPIDOPHORUS, Cuv. & Val. 

 Aspidophorus quadricomis, 



PLATE XXII. 



The specimen is in the British Museum ; and little 

 more seems to be known regarding it, than that it 

 was taken on the coast of Karatschatka. 



The pigment of the skin in fishes, corresponding 

 to what is termed the rete mucosum in human ana- 

 tomy, as offering the most lively play of colours, 

 from the most delicate silveriness to the brightest 

 golden hues, deserves some mention. 



Every colour, and almost every shade and mix- 

 ture of colours, are exemplified in the surface of 

 fishes; yet these colours are often as fleeting as 

 they are glowing. Often they become changed, or 

 disappear with the life of the animal ; and some- 

 times the mere removal of it from its natural ele- 

 ment destroys all its splendour. It is universally 

 observed in fishes, that the superior part, which is 

 exposed to light, is more vividly coloured than the 

 inferior, which indeed is most commonly pure 

 white ; and even in those fishes, as in the pleuro- 

 nectes^ which swim on the side, the colour is con- 

 fined to that which is presented to the light. 



