374 SMALLER STURGEON. 



according to the food on which it has principally 

 fed ; for which reason it is distinguished in Sweden 

 and other northern regions into Mackrel-Sturgeon, 

 Herring- St urgeon, &c. Dr. Bloch observes that 

 the Linnaean specific character of this fish is not 

 quite correct, since the number of dorsal tubercles 

 varies from eleven to thirteen; neither is the number 

 of the lateral or ventral rows more constant, vary- 

 ing in a similar manner. Some have supposed the 

 tubercles of the Sturgeon to be annually cast, in the 

 same manner as those on Rays. It may be added 

 that the Sturgeon is able to survive some days 

 when taken out of water; the gill-covers being 

 edged by a soft membranaceous border, which by 

 closing accurately, prevents the access of atmo- 

 spheric air to the branchiaB. 



SMALLER STURGEON. 



Acipensei* Schypa. A. rostro ohtuso, oiis diametro tertiam 



partem longiore, cirns rostri apici propioribnSy lahiis hifidis. 



Li7i. Gmel. Guldenst. nov. co?7im,. Petrop. l6. p. 532. 

 Sturgeon with obtuse snout^ a third part larger than the 



diameter of the mouth ; the beards nearer the end of the 



snout^ and the lips bifid. 



It is doubtful whether this be a distinct species, 

 or a variety of the common Sturgeon, from which 

 it principally differs in its smaller size, rarely ex- 

 ceeding the length of five feet, and in the few par- 

 ticulars mentioned in the specific character given 

 by its describer Guldenst adt. It is a native of the 

 Caspian sea, and some of the lakes of Siberia. 



f 



