86 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 
Fulcra rougliisli, not enlarged. Lower lobe of tail rather sharp. Sides 
of tail with regular rhombic plates. Plates mesocentrons, rather rough. 
Anal smaller than dorsal, placed mostly below it. Anterior rays of 
pectoral thickened. “Skin with very small rough points in very 
young examples ; in older ones these ossifications are broader, rough, 
substellate, and more or less regularly arranged in oblique series.” D. 
40-44; A. 2G-30. Dorsal plates 11-14; lateral 27-3G; ventral plates 
11. Atlantic Ocean ; ascending rivers of Europe and Korth America. 
Var. oxyrrSaysacHisis (Mitchill), the American Sturgeon, has the num- 
ber of lateral plates generally fewer — 27-29 instead of 29-3G, as in Euro- 
pean examiiles. The stellate ossifications are also said to be some- 
what rougher than in the European form. Massachusetts to Florida ; 
abundant. 
(L. Syst. Nat.; Giiutlier, viii, 342: Acipenser oxyrhynchus Mitcliill, Trans. Lit. & 
Phil. Soc. N. Y. i, 462, and of most American writers.) 
75. A. tra.aismo9i[t:itiUS Richardson. — White Slurgeon; Columbia Eiver Sturgeon; 
Sacramento Sturgeon. 
Color dark grayish, scarcely olive-tinged, and without stripes. Dor- 
sal shields mesocentrous, with a compressed blnntish spine, which is 
anteriorly often serrated, and followed behind by a compressed keel. 
Lateral shields rather opisthoceiitrous. Skin with stellate roughnesses, 
but smoother than in A. medirostris. Snout sharp in the young, be- 
coming 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 2G in number. Upper lobe of tai[ 
with rhombic plates. First caudal fulcrum, above and below, enlarged 
and granular. Lower lobe of caudal rather sharp and long, not much 
shorter than upi)er. Dorsal plates 12 ; lateral 3G— 10, nsnally about 44 ; 
ventral 10. xVnal fin mostly below dorsal. D. 45 ; A. 28. Depth 7 in 
length ; head 4. Pacific coast, south to Monterey, ascending the Sacra- 
mento, Columbia, and Fraser’s Eivers in large numbers in spring. 
Reaches a weight of 300 to GOO imuuds, and is used as food. 
(Richardson, Fauna Bor.-Amer. iii, 278, 18.36: Acipenser hrachyrliynchus and acuH- 
rostris (young) Ayres, Proc. Cal. Acad. Nat. Sci. 1854, 15, 16 : Acipenser transmontanus 
and brachyrhynelius Giiuthcr, viii, 336, 337.) 
76. A. mcslirostris 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 op- 
posite the vent. Shields generally opisthocentrous, with a strongly 
