FUEK-GILLED CIION DROPTERVGIANS. 239 



dorsal is behind the ventrals, and the anal under it. The caudal sur- 

 rounds 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, 

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

 oesophagus by a wide hole. 



The Sturgeon ascends certain rivers in great numbers from the sea, 

 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, L. ; 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 themselves into the Black and Caspian 

 seas, in addition to the sturio, produce three other species, and per- 

 haps more*. 



A. ruthenus, L.; A. pygmceus, Pall., Bl. 89. (The Small 

 Sturgeon or Sterlet). Seldom more than two feet in length; plates 

 of the lateral rows more numerous and carinated, those of the belly 

 fiat. 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 antients J. 



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 prodigiously abundant, but 

 is less valued than the Sturgeon. 



A. huso, L. ; Bl. 129; the Hansen, &c. (The Hausen, or Great 

 Sturgeon). Blunter plates and a shorter snout and cirri than those 

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

 found to exceed twelve and fifteen feet in length, and to weigh more 

 than twelve hundred pounds. One specimen was captured whose 

 weight amounted to near three thousand pounds. The flesh is not 

 much esteemed, and is sometimes unwholesome, but the finest isin- 

 glass is made from its natatory bladder. It is also found in the 

 Po. 



North America has several species of this genus which are pecu- 

 liar to itt. 



* 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 wi;h Kramer, Guldenstedt, 

 or Lepechin. The figures of Marsigli, on the other hand, are too coarse. W e ex- 

 ter ones from the Learned Austrian naturalists, to whom the Danube offers 

 abundance of these ii 



f See my note on Pliny, Lemair's Ed. vol. II, p. 7!. 



t Acip. oxyrhynchux, Lesneur, Amer. Philos. Trans., new series, vol. 1, p. 394; — 

 Aiip. breviroslris, Id.. lb. 390—./.". rubkimdus, Id., lb. 388, and pi. xii, which ap- 

 pears to bear a close resemblance to the Sterlet; — Ac. maculusus, Id., lb. 392, ap- 



