375 



ISINGLASS STURGEON. 



Acipenser Huso. A. fusco-cmrulescens, tuber ciilis later alibus 



siibobsoletis, abdomine svbargenteo. 

 Dusky-blueish Sturgeon, with somewhat obliterated lateral 



tubercles, and slightly silvery abdomen. 

 Acipenser Huso. A. cirris quatuor, squamis dorsalibus tredecim, 



caudalibus quadraginta-tribus. Liji, Syst. Nat. 

 Acipenser apertura branchial i partim nuda. Block, t. 129. 

 Huso. Aldr. pise. p. .534. Jonst. pise, t. 25. f. 1. 3. 



A LARGER fish than the common Sturgeon, having 

 been often found of the length of twenty-five feet : 

 general shape the same ; colour dusky or blackish 

 blue above, silvery on the sides and abdomen, with 

 a tinge of rose-colour on the latter : general ap- 

 pearance smoother than in the common Sturgeon, 

 the dorsal tubercles being less protuberant, and 

 those along the sides much smaller, and in some 

 specimens of a very advanced growth altogether 

 wanting: mouth much larger than in the A. Sturio^ 

 with thick, crescent-shaped lips : skin smooth and 

 viscid. Native of the Northern, Caspian, and 

 Mediterranean seas, migrating from them into the 

 adjoining rivers : found more particularly in the 

 Voljya and the Danube. 



It is from the sound or air-bladder of this species 

 that the well-known substance called isinglass is 

 prepared : this is done by cleansing, splitting, and 

 drying that part, either in the air, or occasionally 

 by a fire, and either twisting or flattening it, ac- 

 cording to the particular sorts by which it is distin- 

 guished in commerce. An ample account of the 



