CHONDROPTERYGII. 661 



covered by the skin. Their decided departure from the class 

 of fish, and approximation to that of the red blooded worms, 

 has been already alluded to in the text. 



Ammocoetes brancltialis has very small or rudimentary 

 eyes, covered with a membrane ; the dorsal fin is very low 

 and terminates in a bent line, the back is greenish, the sides 

 are yellow, and the belly is white. The usual length is about 

 seven inches. They subsist on worms, insects, and carrion. 

 Linnaeus named them branchialis, from the notion of their 

 attaching themselves to the gills of fishes, but this is not 

 verified by observation. They are eaten by those who can 

 overcome their repugnance to the worm-like appearance of 

 these fish, an appearance evidently by no means merely 

 ideal. 



The red Ammocoetes has very small eyes, and the tail fin 

 sublanceolate. It is of a blood-red colour, deeper on the 

 back than the sides, and thereby still more assimilated to the 

 worms. It is found in the Seine, in Normandy. 



We shall conclude our Supplement on Fish, with some 

 observations 1 on the importance to mankind of this class of 

 animals, viewed as articles of nutriment and commerce. 



When we contemplate the vast number of genera and 

 species of fish already known, and reflect that in all proba- 

 bility numerous additions will continue to be made to the 

 catalogue for a considerable time to come ; that an immense 

 number of species exist through the mighty expanse of 

 waters, in rivers, lakes, seas, and oceans ; we are naturally 

 led to inquire, to what end these congregations, these shoals 

 of beings, teeming with life and resplendent in beauty, are 

 thus cast abroad ; for what purpose they have received, above 



1 By Colonel Hamilton Smith. 



