38 



as the number of these sturgeons examined by all the ichthy- 

 ologists of America taken together, doubtless falls far short of 

 five hundred, it is not remarkable that it has hitherto been 

 overlooked. 



Recognizing, as we are disposed to do, the generic criteria 

 proposed for the scaphirhynchoids by Berg ('04), we regard this 

 form as generically distinct from species hitherto described. 



Parascaphirhynchxs, gen. nov. 



Snout broad, shovel-shaped ; caudal peduncle long and 

 flattened above, broader than deep, and completely covered by 

 scutes. Breast and belly naked, sides sprinkled with small 

 discoidal ossifications. Lips four-lobed ; spiracles and pseudo- 

 branchs wanting ; gill-rakers fan-shaped, two- or three-pointed 

 on the lower half of the arch ; ribs twenty or twenty-one ; 

 air-bladder well developed, about 8 times in length of head and 

 body. 



One species; known at present only from the Mississippi 

 River. 



Parascaphirhynchus albus, sp. nov. 



Head long, 2.9 to 3.2 in total length, and the body compar- 

 atively short ; depth, 7.5 to 9 in length of head and body ; dis- 

 tance from gill-cavity to front of dorsal 2.5 in total length. 

 Color very light, the upper parts bluish gray in life, the lower 

 parts of the sides and belly shading from very light gray to 

 almost milky white. 



Scutes small (PI. VI.), sixteen to nineteen in the dorsal 

 tow, forty-one to forty-seven in the lateral, and ten to thirteen 

 in the ventral. Spines of the dorsal and lateral scutes sharp, 

 projecting strongly backward, and reaching to near the poste- 

 rior border of the scute. Denticulated ossifications between 

 the dorsal and lateral, and lateral and ventral rows of scutes 

 diminishing in size and abundance from above downward. A 

 few imperfect plates along the dorsal row of scutes, extending 

 as far forward as the backward reach of the pectorals, more 

 numerous and larger backwards, and becoming continuous with 



