FISHES 55 



many species, all North American except C. rostratus Tilesius, which 

 occurs in Siberia. 



Key to the Species of Catostomus here described 



ai More than 80 scales in the lateral line. 



bi Upper lip broad, with 5 or 6 rows of papillae. 



Ci Upper lip not projecting; in the Colorado River basin. 



di In the lower Colorado basin C. latipinnis. 



d2 In the upper Colorado basin C. discobolus. 



C2 Upper lip very long and pendant; in the upper Missouri. .C. griseiis. 

 bi Upper lip narrow, with about 3 rows of papillae. 



Ci In the northern United States C. catostomus. 



Ci In Lake Tahoe C. tahoensis. 



3.2 Less than 75 scales in the lateral line, 

 bi In the western States. 

 Ci On the Pacific slope. 



di In California C. occidentalis. 



C. mniotiltus. 



6.2 In Oregon C. tsiltcoosensis. 



ds In Oregon and California C. snyderi. 



C. mlcrops. 

 Co In the Great Basin and the Rocky ^Mountains. 



di From Oregon to Montana C. macrocheilus. 



d2 In Utah C. ardens. 



hn In the eastern and central States C. commersonii. 



C. latipinnis Baird & Girard. Length 600 mm.; head 4; depth 5.5; 

 color dark olive; sides and fins orange; rays of dorsal fin 14 or 15; anal 

 7; scales 19-89 to 102-18, 46 to 50 before the dorsal fin; lips very thick, 

 the lower extending backward to beneath the eye; fins very large: 

 basins of the lower Colorado; common. 



C. discobolus Cope. Length 300 mm. or more; head 3.8 to 4.5; 

 depth 5.25; rays of dorsal fin 12 or 13; anal 7; scales 19 to 21-101 to 109- 

 17 to 21, 52 to 63 before the dorsal fin; mouth as in C. latipinnis; 

 muzzle extending to slightly beyond upper lip: upper Colorado basin; 

 Montana. 



C. griseus (Girard). Length 500 mm.; head 4; depth 5.5; color 

 brown; rays of dorsal fin 10 to 12; scales 16-90 to 1 10-14; upper lip very 

 long and pendant; lower lip deeply incised: upper Missouri basin; 

 abundant in the Yellowstone. 



C. catostomus (Forster). Long-nose sucker. Length 750 mm.; 

 head 4.5 ; depth 4.5 ; rays of dorsal fin 10 to 1 1 ; anal 7 ; scales 14 to 1 7-95 

 to 117-13; upper Hp with 2 to 4 rows of tubercles; lower lip deeply 

 incised; mouth inferior; head very long and slender, the snout over- 

 hanging the mouth: from Maine and the basin of the St. Lawrence 



