88 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



48.— SCAPHIRRHYWCIIOPS Gill. 

 Shovel-nose Sturgeons. 



(ScaphirhyncJiiis Heckel, Ann. Wiener Mus. Naturgesch. i, 1835, 71 ; preoccupied in orui- 



tbology. ) 

 {Scaphirhynchojjs* (Gill, MSS.) Jordan & Copeland, Bull. Buff. Soc. Nat. Hist. 1876, 161 ; 



tyjte Acipenser platorynchus Rafinesque.) 



Snout broad, depressed, subspatulate or sliovel-shaped. No spiracle. 

 Caudal peduncle very long, strongly depressed, broader than deep. 

 Rows of bony bucklers confluent below the dorsal fin, forming a com- 

 plete coat of mail on the tail. Tail i)roduced in a filament beyond the 

 caudal fin. Gill-rakers somewhat fan-shaped. Pseudobranchise obso- 

 lete. Species about 4, inhabiting the fresh waters of the United States 

 and Central and Eastern Asia. {(T-/.d<fr], spade; poyxo^, snout; w(//, appear- 

 ance.) 



79* S. platyrrliyncBius (Rafinesque) Gill. — Shovel-nosed Sturgeon; White Sturgeon. 

 Body elongate, tapering into a slender, depressed tail, which extends 

 beyond the caudal fin in the form of a filament. This filament is long 

 and slender in the young, but is frequently lost in the adult. Bony 

 shields opisthocentrous, sharx)lj^ keeled, the series confluent below the 

 dorsal, obliteratirig the smaller plates between. Two occipital plates 

 ■with short keels. A spine in front of eye, and one at the posterior edge 

 of the rostral " shovel " ; snout in the young with a few spines. Barbels 

 nearer mouth than tip of snout. Greatest width of head about half its 

 length. Kone of the fulcra enlarged. Dorsal and anal small. Anal 

 partly below dorsal. Gill-rakers small, lamellate, somewhat fan-shaped, 

 ending in 3-4 x^oints. Dorsal shields 15-18 ; lateral 41-46 ; ventral 11- 

 13. Head 4 in length. L. 5 feet. Mississippi Valley and streams of 

 the Western and Southern States ; common. 



(Acijienser platorhynchns Rafinesque, Ichth. Oh. 1820, 80: Scaphirhijnchus rafinesquei 

 Heckel, Ann. Wiener Mus. Naturgesch. i, 1835, 71 : Scaphirhynchus cataphractus Giiuther, 

 viii, 345.) 



Subclass HOLOSTEI. 



{The Bony Ganoids.) 



Skeleton bony. Ventral fin abdominal, with the basilar segments rudi- 

 mentary, as in ordinary fishes. Primary radii of posterior limb generally 

 reduced to one rudiment. Suboperculum and preoperculum present. 



* " In words beginning with p, p is doubled after a prefix " (Liddell ^ Scott, Gr.-Engl. 

 Lex. 1858, 213) ; hence ScapMrrhynchops, Hemirrhamphiis, and all similar words are 

 properly written with the double r. 



