FISHES »I 



Arkansas; basin of the Tennessee River; rather common in sandy 

 streams. 



P. uranops Cope. Length loo mm.; head 4.75; depth 6; color pale 

 olivaceous, with a dark spot at the base of the tail fin; scales 7-60-6: 

 upper Tennessee basin; common in the river channels. 



P. catostomus Jordan. Length 100 mm.; head 4.5; depth 5.6; color 

 olivaceous, with a silvery lateral band, dark at the base of the tail fin; 

 scales 7-60-5: Alabama River basin; common. 



42. Rhinichthys Agassiz. Body elongate; head long and slender; 

 a minute barbel on the maxillary; teeth mostly 2, 4-4, i or 2, hooked; 

 scales small; dorsal hn behind the ventrals; coloration dark; males rosy 

 in the spring: 3 species, i in Mexico. 



a b 



Fig. 37. — Head of Phenacobius mirabilis: a, side view; b, ventral view {from Fishes of 



Illinois). 



R. cataractce (Cuvier & Valenciennes). Long nosed dace. Length 

 125 mm.; head 4; depth 5 to 5.5; color dark olive, paler below; back 

 almost black; a dark spot on the opercle; body elongate; head long; 

 mouth inferior; rays of dorsal fin 8; anal 7; scales 65: New England 

 to the Columbia; southward to North Carolina and the Great Salt 

 Lake basin; in swift streams; common and variable. 



R. atronasus (Mitchill). Black nosed dace. Length 75 mm.; head 

 4; depth 4.5; color blackish, with a black lateral band; males in spring 

 with the lateral band, lower tins and sometimes the whole body crimson, 

 the lateral band in late summer becoming orange and later getting dark ; 

 rays of dorsal fin 7; anal 7; scales 64; teeth 2, 4-4, 2: New England to 

 Minnesota; southward to Alabama; very common in clear brooks; 

 very variable. 



43. Apocope Cope. Similar to Rhinichthys except that the pre- 

 maxillaries are protractile; rays of dorsal fin mostly 8; anal 7:10 species, 

 all in the Rocky Mountain region. 



Key to the Species of Apocope 



ai Teeth, i, 4-4, i. 



bi Dorsal fin with 8 rays. 



Ci Scales small, more than 70 in the lateral line. 



di Scales about 89 4. oscula. 



