Caudal peduncle less extreme 192. 



190. Scale count about 65; California 



Lavinia exilicauda B. & G. Hitch 

 Scale count about 80; Gila and Colorado Rivers 191. 



191. Scales scarcely overlapping, much reduced on back and belly; about a 



foot long 



Gila elegans B. &? G. Bonytail, Gila Trout 

 Scales slightly overlapping, not so much reduced on back and belly; 

 somewhat larger in the adult 



Gila rohusta B. 5? G. Roundtail 



192. Snout very long, resembling a pickerel's, with the distance from the eye 



to the end of the snout more than twice the diameter of the eye; phar' 



yngeal teeth 4-5 or 5'5; very large fishes, getting to be three to five 



feet long; western species 193. 



Snout shorter; si2;e smaller 194. 



193. Body slender, more than five times as long as deep; getting to be five feet 



long; Colorado River Valley 



Ptychocheilus lucius Girard White Salmon 

 Body not so slender; getting to be somewhat over three feet long; Pacific 

 states 



Ptychocheilus oregonensis (Richardson) Squawfish, Chappaul 



194. Premaxillaries not protractile 195. 

 Premaxillaries protractile 197. 



195. Lips thin; scale count over 60; Maine to Minn, and southwards 



Rhinichthys atronasus (Mitchill) Black-nosed Dace 

 Rhinichthys atratulus (Hermann) 

 (Includes R. meleagris Agassiz,) 

 Lips thick or lobed; scale count less than 60 196. 



196. Lips thick but not lobed; eastern states 



Parexoglossum laurae Hubbs Eastern Tongue-tied Minnow 

 Lower lip with a fleshy lobe on each side; N. Y. to Virginia 

 Exoglossum maxillingua (LeSueur) Cut-lips 



197. Lower lip with a fleshy lobe on each side; central states 



Phenacohius mirahihs (Girard) Sucker-mouthed Minnow 

 Lower lip not lobed 198. 



198. Intestine wound spirally around the air bladder; ridge of lower jaw 



separated by a distinct groove from the lower lip; color brownish; 

 N. Y. to Texas 



Campostoma anomalum (Raf.) Stone-roller 

 Intestine not so; ridge of lower jaw usually less set off from lip; color 

 various 199. 



199. Herbivorous or mud-eaters; intestine more than twice as long as the body, 



the contents often visible through the body wall as a dark mass; lining 

 of body cavity usually dark; belly often appearing swollen 200. 



Carnivorous; intestine less than two times the body length; lining of 

 body cavity pale in most but not all species; belly usually narrower 



206. 



280 



