182 



VERTEBRATA. PISCES. 



are armed with regular spinous tubercles, it assumes 

 an angular form. The snout is long and tapering, 

 beneath which is placed the mouth, in the form of 

 a fleshy tube, without teeth. The upper lobe of 

 the tail-fin is much longer than the lower. They 

 are usually rather large fishes, inhabiting the rivers, 

 but annually migrating to the sea. The flesh of 

 most of them is esteemed ; the roe is converted 

 into caviare, and the air-bladder into isinglass. The 

 common Sturgeon (A. Sturio) is now and then taken 



THE STURGEON (Adpenser Sturio). 



on our coasts and in our rivers ; and a few years ago, 

 more than a hundred were brought to Billingsgate 

 market in the course of one season. One taken in 

 Scotland, in 1833, was eight and a half feet long, 



