Platte River Sucker 



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

 ing backwaid 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; tins 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 2 

 feet or less. 



Platte River Sucker 



Catostonius griscus (Girard) 



Upper Missouri River basin, particularly abundant in the Platte 

 and the Yellowstone. 



This species is close to C caiostomus, apparently differing chiefly 

 in the larger mouth and the broader upper lip. 



Head 4 in body; depth si; D. 10 to 12; scales 16-90 to 1 10-14. 

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

 essentially that of C. cafostotiiiis] head large, the interorbital space 

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

 posterior; mouth large, about as in C. lalipiniiis, 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. 



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