CHONDROPTERYGII BRANGHIIS LIBERIS. 279 



protractile than that of the Shark. The eyes and nostrils are on the 

 side of the head, and cirri are inserted under the snout. The laby- 

 rinth is perfectly formed in the cranial bone, but there is no vestige 

 of an external ear. A hole perforated behind the temple is a mere 

 spiracle, which leads to the branchiae. The dorsal is behind the ven- 

 trals, and the anal under it. The caudal surrounds the extremity of 

 the spine and has a salient lobe beneath, shorter, however, than its 

 principal point. Internally, we already find the spinal valve of the 

 intestine and the united pancreas of the Selachii, but there is, more- 

 over, a very large natatory bladder, which communicates with the 

 oesophagus by a wide hole. 



The Sturgeon ascends certain rivers in great numbers, and is the 

 object of important fisheries; the flesh of most species is agreeable, 

 their ova are converted into caviar, and their natatory bladder into 

 isinglass. Western Europe produces 



A. sturio, h.; Bl., 88. (The Common Sturgeon.) Six or 

 seven feet long; snout pointed; plates strong and spinous, 

 arranged in five rows; the flesh resembling veal. 



The rivers which empty into the Black and Caspian seas, in 

 addition to the sturio, produce three other species, and perhaps 

 more.(l) 



A. Riithenus, L.; A. pygmosus, Pall., BL, 89. (The Sterlet.) 

 Seldom more than two feet in length; plates of the lateral rows 

 more numerous and carinated, those of the belly flat. It is 

 considered a delicious fish, and its caviar is reserved for the 

 Russian court. There is reason to believe that it is the Elops 

 and the Acipenser, so highly celebrated among the ancients. (2) 

 A. helops, Pall.; A. stellatus, Bl. Schn.; Marsill., Dan. IV,xii, 

 2; the Scherg of the Germans; Sevreja of the Russians. Four 

 feet in length, and has a longer and more slender snout, and 

 rougher plates than the others. This species is excessively 

 numerous, but is less valued than the Sturgeon. 



A. Jmso, L.; Bl., 129; the Hansen, Sec. (The Great Sturgeon.) 

 Blunter plates and a shorter snout and cirri than those of the 

 Common Sturgeon; the skin also is smoother. It is frequently 



(1) The various species of the Sturgeon are not yet well determined, and even 

 Pallas, who knew more of them than any one else, does not give them sufficiently 

 distinct comparative characters; he does not agree either with Kramer, Gulden- 

 stedt, or Lechepin. The figures of Marsigli, on the other hand, are too coarse. 

 Wc expect better ones from the learned Austrian naturalists, to whom the Da- 

 nube offers abundance of these fishes. 



(2) See my note on Pliny, Lemaire's Ed. vol. II, p. 74. 



