104 Bulletin 47, United States National Museum. 



c. Shields all roughly striated aud ridged; anal nearly as long as dorsal and almost 



entirely behind it. D. 33 ; A. 22. Dorsal shields about 9; lateral about 26; 



ventral about 8. Color decidedly greenish. MEDIROSTRIS, 146. 



cc Shields not roughly striated; anal a little more than % length of dorsal and 



almost entirely below it. D. 38 ; A. 27. Dorsal shields about 10; lateral 29; 



ventral 9. Color grayish. . STURIO, 147. 



bb. Space between dorsal and lateral shields with minute spinules in very many series. 



d. Last dorsal shield of moderate size, more than % the one before it. Anal 1*> in 



dorsal and beginning below its middle. Dorsal shields about 15; lateral 38; 



ventral 10. D. 35; A. 37. RUBICUNDUS, 148. 



dd. Last dorsal shield very small, Jess than % length of the one before it; dorsal 



shields 11; lateral 32; ventral 9. D. 41; A. 22. Anal entirely below dorsal and 



% as long. BEEV1HOSTRUM, 149. 



145. ACIPENSER TRANSMONTANUS, Richardson. 

 (WHITE STURGEON; OREGON STURGEON; SACRAMENTO STURGEON.) 



Color dark grayish, scarcely olive tingedj and without stripes. Dor- 

 sal shields mesocentrous, with a compressed bluntish spine, which is 

 anteriorly often serrated, and followed behind by a compressed keel. Skin 

 with stellate roughnesses, but smoother than in A. medirostiis. Space 

 between lateral shields with stellate plates of moderate size, in about 5 

 series interspersed with smaller ones ; last dorsal shield i length of one 

 before it. Snout sharp in the young, becoming rather blunt and short 

 in the adult, when it is considerably shorter than the rest of the head. 

 Barbels rather nearer to the tip of snout than to the mouth. Gill rakers 

 comparatively long, more than 3 times as high as broad, about 26 in 

 number. Upper lobe of tail with rhombic plates. First caudal fulcrum, 

 above and below, enlarged and granular. Lower lobe of caudal rather 

 sharp and long, not much shorter than upper. Dorsal plates 11 or 12 ; 

 lateral 36 to 50, usually about 44 ; ventral 10 to 12. Anal fin below dorsal, 

 its base about i as long. D. 45 (44 to 48); A. 28 to 30. Depth 7 in length ; 

 head 4. Pacific coast from Alaska south to Monterey, ascending the 

 Sacramento, Columbia, and Fraser rivers in large numbers in spring. 

 It reaches a weight of 300 to 600 pounds, and is largely used as food, but 

 is rather coarse, (transmontanus, beyond mountains.) 



Acipemer transmontanus, RICHARDSON, Fauna Bor. Amer., in, 278, 1836; Fort Vancouver. 

 Acipemer brachyrhynchus, acd acutiroslris (youug), AYRES, Proc. Cal. Ac. Sci., 1854, 15, 16, San 



Francisco. 



Acipenser transmontanus and brachyrhynchus, GUNTHER, Cat., vin, 336, 337, 1870. 

 Acipemer transmontanus, JORDAN & GILBERT, Synopsis, 86, 1883. 

 f Acipenser aleuleitsis, FITZINGER & HECKEL, Ann. Wien. Mus., 1836, Aleutian Islands, after 



Pallas. 

 Acipemer caryi, ayresi, and putnami, DUMERIL, Nouv. Arch. Mus., in, 169, 171, 178, 1867, San 



Francisco. 

 Acipenser transmontanus, KIBSCH & FORDICE, * Proc. Ac. Nat. Sci. Phila., 1889, 254. 



146. ACIPENSER MEDIROSTRIS, Ayres. 



(GREEN STURGEON.) 



Color olive-green, with an olive stripe on the median line of the belly 

 and one on each side above the ventral plates, these stripes ceasing 



* This paper contains descriptions and synonymy of all the American Sturgeons. 



