ACIPENSER.] PISCES (CARTILAG.) ELEUTHEROP. 493 



(II. CARTILAGINEI.) 



ORDER VI. ELEUTHEROPOMI. 



GEN. 71. ACIPENSER, Linn. 



182. A. Sturio, Linn. (Common Sturgeon.) Osseous 

 tubercles in five longitudinal rows ; strong and spinous. 



A. Sturio, Linn. Syst. Nat. torn. i. p. 403. Block, Ichth. pi. 88. 

 Turt. Brit. Faun. p. 114. Don. Brit. Fish. vol. HI. pi. 65. Flem. 

 Brit. An. p. 173. Sturio, Will. Hist. Pise. p. 239. tab. P. 7. fig. 3. 

 Sturgeon, Penn. Brit. ZooL vol. in. p. 124. pi. 19. no. 53. Com- 

 mon Sturgeon, Id. (Edit. 1812.) vol. in. p. 164. pi. 22. L'Esturgeon 

 ordinaire, Cuv. Reg. An. torn. 11. p. 379. 



LENGTH. From six to eight feet, sometimes more. 



DE SCRIPT. (Form.) Body elongated ; somewhat pentagonal ; with five 

 longitudinal rows of osseous tubercles, one on the back, two at the sides, 

 and two at the edges of the abdomen ; tubercles marked with radiating 

 strise, broad at the base, terminating above in a sharp strong spine 

 directed backwards ; those on the back more developed than the others : 

 the whole skin rough with minute points and tubercles independently 

 of the above larger ones: abdomen flat: head long, covered above 

 with lozenge-shaped plates; a longitudinal sulcus on the forehead: 

 snout depressed, somewhat conical, rather slender and sharp-pointed ; 

 mouth placed beneath, cylindrical, small, without teeth, bordered by a 

 protractile cartilage instead of lips : four pendent barbules on the under 

 surface of the snout, nearer its extremity than the mouth : eyes small : 

 nostrils near the eyes, double; the anterior orifice round, the posterior 

 one elongated : gill-opening large ; the gill-cover marked with numerous 

 stria?, radiating in all directions: a single dorsal, of a somewhat tri- 

 angular form, small, placed very far back near the tail: anal also small, 

 and nearly opposite : caudal forked ; the upper lobe long and pointed, 

 produced very much beyond the lower : pectorals' oval : vent beneath the 

 commencement of the dorsal ; the ventral fins a little in advance of it. 



D. 35 ; A. 23 ; C. 125; P. 28 ; V. 24*. 



(Colours.) Upper parts gray, variegated with dusky, sometimes inclining 

 to olivaceous ; the central part of the tubercles white : beneath silvery 

 white. 



A migratory species, residing in the sea during the winter months, 

 but entering rivers at the approach of Spring to spawn. Very abundant 

 in many parts of the Continent, but seldom in any plenty in this country. 

 Attains to the weight of from one hundred to three hundred pounds, 



* The above fin-ray formula is from Donovan, 



