PARASCAPHIRHYXCHUS — WHITE STURGEON 29 



branes continued backward on each side so as to cover the anterior 

 fourth of the pectoral shields; gill-rakers 10 or 11, +3, 2- or 3 -pointed on 

 lower half of arch, the two rows of each arch separated by a broad smooth 

 surface. Dorsal rays 35 to 43, the base of the fin 11.8 to 12.8 in length 

 of head and body; anal rays 20 to 23, ventral 23 to 26, pectoral 43 to 

 49; caudal filament scarcely developed. Dorsal scutes 16 to 19, lateral 

 41 to 47, ventral 10 to 13; spines of dorsal and lateral scutes usually 

 not far from even with their posterior margin ; area between dorsal and 

 lateral and between lateral and ventral series of scutes more or less 

 densely covered with small denticulated ossifications, diminishing in 

 size and abundance from above downward ; some im^perfectly formed 

 plates along base of dorsal row of shields as far forward as the backw^ard 

 reach of the pectorals, these plates becoming more numerous and larger 

 farther back, where they are continuous with those which roof the 

 caudal peduncle ; belly wholly naked to front of ventrals ; breast with 

 a fe-\^' bony points similar to those on the lower part of the sides. 



This species is known to us at present only from the Mississippi 

 River at Grafton and Alton, Illinois. It is rare in the catches at 

 those places, only one in three hundred of the shovel-nosed sturgeons 

 taken belonging to this species. It is said by Mr. H. L. iVshlock, 

 who first brought the fish to our notice, to be somew^hat commoner 

 in the lower Missouri. The spawning season is between June 1 and 

 August 1. The sexual differences are unknown, all our seven 

 specimens being males. The fish is said by Mr. Ashlock to prefer 

 swifter water than the common shovel-nose. The stomachs of the 

 seven types were nearly empty, and the greatly comminuted matter 

 which they contained was wholly unidentifiable. 



