SUPPLEMENT 



ON THE 



CHONDROPTERYGII. 



ORDER I. STURIONES. 



The second series of this class of animals, or the cartilagi- 

 nous fish, begins, as we have seen, with the Sturiones, or 

 Sturgeons, or those with the gills unattached on the outer 

 edge, with a common opening as distinct from the sharks, 

 and having the exterior edges of the gills attached to the 

 flesh, with the water passing through them, and out at 

 several distinct openings. 



The sturgeon in outward form a good deal resembles the 

 sharks, but instead of teeth, the former possesses merely a 

 hard cartilage on the jaws, which, with the small size of the 

 mouth, unfits these fish for any great predatory exertions. 

 The mouth moreover is capable of some elongation and con- 

 traction, but is small and purse-like. Their disposition, in 

 conformity with their want of power, notwithstanding their 

 great size, is consequently and by comparison, gentle and 

 unoffending. The barbels attached to the mouth are very 

 slender, mobile, and vermiform ; and it is even said, that 

 sturgeons have a habit of lying concealed in the mud and 

 weeds, leaving only their wormlike barbels visible, to attract 

 the attention of small fish, which, on approaching these 



