68 VERTEBRATE ANIMALS OF THE UNITED STATES 



13. Mylocheilus Agassiz. Body elongate; upper jaw protractile 

 with a small barbel on the maxillary ; size large : i species. 



M. lateralis Agassiz & Pickering. Whitefish; chub. Length 300 

 mm.; head 4.2; depth 4.5; color dark above and pale beneath; sides 

 silvery, with two dark lateral bands enclosing a silvery band; teeth 

 I or 2. 5-5, 2 or I ; rays of dorsal fin 8; scales 12-77-7: Oregon into 

 British Columbia to the Fraser River; eastward to Flathead Lake; 

 often enters the sea; abundant; a good food fish. 



14. Leucosomus Meckel. Similar to Semotilus; size large; scales 

 not crowded anteriorly: i species. 



L. corporalis (Mitchill). Fallfish; chub. Length 450 mm.; head 

 and depth 4; color steel blue above; sides and belly silvery; males in 

 spring with belly and fins red; rays of dorsal fin 8; anal 8; dorsal fin 

 half way between nostril and tail fin; scales 8-45-4, about 22 before 

 the dorsal fin : from Maine and the St. Lawrence to the James, east of the 

 Alleghanies; common in swift streams and clear lakes; a game and food 

 fish. 



15. Semotilus Rafinesque. Body stout ; head large ; upper jaw pro- 

 tractile; a minute barbel on the maxillary just above its extremity; teeth 

 2, 5-4. 2, hooked; size large: 2 species. 



5. atromaculatus (Mitch.) (Fig. 30) Horned dace; common chub 

 Length 250 mm.; head 3.75 ; depth 4; color dusky bluish; dorsal fin with 

 a conspicuous black spot at its base and bordered by red in front in the 

 male; teeth variable; rays of dorsal fin 7; anal 8; scales 9 to 11-55 to 

 69-5 to 7; dorsal fin midway between pupil and tail fin: from Maine to 

 Wyoming; southward to Alabama; common, chiefly in small streams. 



16. Pogonichthys Girard. Body elongate ; maxillary with a barbel; 

 caudal fin asymmetrical, the upper lobe being much the longer; size 

 large: i species. 



P. macrolepidotus (Ayres). Split-tail. Length 300 mm.; head 4.2; 

 depth 3.75; teeth 2, 5-5, 2, hooked; color uniform, sides silvery; rays of 

 dorsal fin 9; anal 8; scales 10-66-6: central California; common. 



17. Ptychocheilus Agassiz. Body elongate; caudal peduncle stout; 

 no barbels; teeth 2, 5-4, 2; scales small; lateral line decurved; size very 

 large : 4 species. 



P. oregonensis (Richardson). Squawfish. Length up to 1,200 mm.; 

 head 3.75; depth 5; color greenish; belly silvery; rays of dorsal fin 10; 

 anal 8; scales 20-70: extreme northwest, ascending the Columbia and 

 tributaries into Montana; common; a food and game fish. 



P. umpqucB Snyder. Similar to P. oregonensis; scales 75 to 80: 

 coastal streams of central Oregon. 



