Platte River Sucker 



developed, the lower incised to the base, its posterior margin extend- 

 ing backward to opposite the eye; tubercles on lower lip small 

 behind; jaws with a slight cartilaginous sheath; eye small and high 

 up; scales long and low, posteriorly rounded; fins greatly developed, 

 especially in old males, the free border of the dorsal deeply incised; 

 height of vertical fins in the male greater than length of head; origin- 

 of dorsal nearer snout than base of caudal; caudal very strong, the 

 rudimentary rays unusually developed. Colour, dark olive, abruptly 

 paler below; sides and fins largely orange in both sexes, the anal 

 and lower lobe of caudal tuberculate in breeding males. Length * 

 feet or less, 



Platte River Sucker 



Catostomus grisetts (Girard) 



Upper Missouri River basin, particularly abundant in the Platte 

 and the Yellowstone. 



This species is close tr C. catostomus, apparently differing chiefly 

 in the larger mouth and the broader upper lip. 



Head 4 in body; depth 5^; D. 10 to 12; scales 16-90 to 110-14. 

 Body long and slender, subterete, compressed behind, the form 

 essentially that Of C. catostomus; head large, the interorbital space 

 broad and flat, 2\ in length of head; eye small, high up and rather 

 posterior; mouth large, about as in C. latipinnis, the upper lip very 

 large, pendant, and with 5 to 8 series of tubercles; lower lip incised 

 to base, the lobes long; horny sheath pretty well developed; dorsal 

 fin not long, nor especially elevated, its origin rather nearer base of 

 caudal than tip of snout; caudal long and strongly forked; anal long 

 and high, reaching base of caudal ; ventrals not reaching vent. 

 Colour, dusky brown, sometimes with a dusky lateral band, 

 sometimes irregularly mottled or barred; snout dark. Length i to 

 2 feet. 



