25. ACIPENSERHLE ACIPENSER. 87 



Looted spine. Skin very rough. Snout about as in A. trammontanus, 

 sharp in the young, becoming blunt with age, usually rather shorter 

 than the rest of head. Barbels nearly midway between snout aud 

 mouth. Gill-rakers scarcely higher than broad, about 17 in number. 

 Upper lobe of tail with some scattered plates. Caudal fulcra not en- 

 larged. Lower lobe of caudal short and blunt, little more than half the 

 length of the upper. Dorsal plates 10; lateral 28-30; ventral 9. Anal 

 fin about half below the dorsal. D. 37 ; A. 30. Depth 7-J in length ; 

 head 4^. Pacific coast, ascending the rivers from San Francisco north- 

 ward, reaching a large size. Less abundant than A. transmontanus; 

 not used for food, being reputed poisonous. 



(Ayres, Proc. Cal. Acad. Nat. Sci. i, 15; Giinther, viii, 342: Acipenser agassizi Giiuther, 

 viii, 344 : Acipenser acutirostris Giinther, viii, 344 ; not of Ayres.) 



77. A. rubicundus Le Sueur. Lake Sturgeon; Ohio Sturgeon; Black Sturgeon; 

 Stone Sturgeon ; Lock Sturgeon. 



Blackish above, sides paler or reddish. Body comparatively elongate ; 

 snout slender and long in the young, becoming quite blunt with age, 

 when it is considerably shorter than the rest of the head ; shields large, 

 rough with strongly hooked spines, becoming later comparatively 

 smooth. Skin with minute rough plates. Ventral shields growing 

 smaller with age, and finally deciduous. Dorsal shields 13 (11-16); 

 lateral shields (34) 30-39; ventral plates 8-10. D. 35; A. 26. L. 6 

 feet. Weight 50 to 100 pounds. Mississippi Valley, Great Lakes, and 

 northward. Our common fresh- water sturgeon, usually not descending 

 to the sea. 



(Le Sueur, Trans. Arner. Phil. Soc. i, 1818,388: Acipenser maculosus Le Sueur, Trans. 

 Ainer. Phil. Soc. i, 393: Acipenser rupertianus Richardson, Fauna Bor.-Ainer. iii, 311: 

 Acipenser carbonarius, 1<evis, and rhynchceus Agassiz, Lake Superior, 271, 276 : Acipenser 

 niUcundus, maculosus, and liopeltis Giinther, viii, 333, 339, 341 ; Miliier, Kept. U. S. Fish 

 Com. 1872-73,67.) 



78. A. brevirostris Le Sueur. Short-nosed Sturgeon. 



" Snout very short and obtuse, about one-fourth of the length of the 

 head. Barbels short, simple. Osseous shields rather small and distant 

 from one another, finely radiated and granulated ; 8-10 on the back, 

 22-28 on the sides, 6-8 along the abdomen. Skin very sparingly cov- 

 ered with minute prickles and very small scattered ossifications. The 

 greater part of the anal below the dorsal. D. 30." (Giinlher.) Cape 

 Cod to Florida. 



(Le Sueur, Trans. Amer. Phil. Soc. i, 390 ; Giinther, viii, 341. ) 



