Jordan and Ever mann. Fishes of North America. 233 



fishes, especially to young trout. Varies greatly with age and surround- 

 ings. The present description is taken primarily from Utah Lake speci- 

 mens, typical of L. atrarius. We have examined specimens from Utah 

 Lake, Provo River, Bear River, Jordan River, Sevier River, Heart Lake, 

 and Jackson Lake, Wyoming, and other streams tributary to Snake River.* 

 (lincdtHx, streaked, a character usually not conspicuous, and produced by 

 the paler centers of the scales contrasting with the dotted edges.) 



Tigoma Uneata, GIRARD, Proc. Ac. Nat. Sci. Phila., 1856, 200 ; locality unknown, type loet. 



(Coll. Borkwith.) 

 Ti.joma obesa, GIRARD, Proc. Ac. Nat. Sci. Phila., 1866, 206, Salt Lake Valley; and Pac. B. R. 



Surv., x, 290, 1858 ; the name obesus preoccupied in Leuciscus. (Type, No. 2773. Coll. Bow- 

 man.) 

 Siboma atraria, GIRARD, Proc. Ac. Nat. Sci. Phila., 1856, 208, Utah District near the Desert, 



(Coll. Bockwith) ; and Pac. B. B. Surv., x, 297, 1858. 

 Tigoma synamata, GILL, Proc. Bost. Soc. Nat. Hist., 1861, 42; and Ichth. Capt. Simpson's Expl., 



1876, 405, Salt Lake Basin ; a very deep-bodied example; scales 10-50-3. (Type, No. 2607. 



Coll. C. S. McCarthy.) 

 P)-otoporus domninus, COPE, Hayden's Geol. Surv. Mont, for 1871, 473, 1872, Snake River, Fort 



Hall, Idaho, (Coll. Carrington); a very young example with incomplete lateral line and 



teeth 2,4-4, 1; scales 9-56-6; JORDAN & GILBERT, Synopsis, 203, 1883. 

 HybopsisbiviUatus, COPE, Hayden's Geol. Surv. Mont, for 1871, 1872, 474, Warm Springs, Utah, 



(Coll. Carrington); young with teeth 2, 4-4, 2 ; scales 12-53-11. 

 llybopsi* liiujHtiiotjeHxla, COPE, Proc. Amer. Philos. Soc. Phila., 1874, 134, Timpanogos, Utah; 



young with incomplete lateral line ; scales 13-52-2, and teeth 2, 4-4, 2. (Type, No. 15769. 



Coll. F. Klett); COPE & YARROW, Zool. Wheeler Surv., 654, 1875. 

 Siboma alraria, and variety longiceps,^ COPE, Zool. Wheeler Surv., 667, 1875, (1876), Snake Creek 



Valley, Nevada, near the Utah line, and near the Sevier Basin, belonging to 



the drainage of Lake Bonneville. (Type, Nos. 12910, 15770, 15782. Coll. Yarrow; 



C. G. Newberry.) 

 Squalius rhomalem, JORDAN & GILBERT, Proc. U. S. Nat. Mus., 1880, 461, very old ; scales 10-55-5, 



Utah Lake. (Coll. Jordan.) 

 Squalius cmoreus, JORDAN & GILBERT, I. c., 400, 1880, Provo River; scales 11-56-6 ; young. 



(Type, No. 30806. Coll. Madsen.) 



Minnilus bivittatus, JORDAN & GILBERT, Synopsis, 195, 1883. 

 Mi,i,iili<s thiijxniuijfiisis, JORDAN & GILBERT, Synopsis, 196, 1883. 

 S'lualiits cntoreus and rhomaletis, JORDAN & GILBERT, Synopsis, 234, 240, 1883. 

 Sqitalim lineatus, JORDAN & GILBERT, Synopsis, 236, 1883. 

 Sqnalius obesus, JORDAN & GILBERT, Synopsis, 237, 1883. 



Squalius alrariux, JORDAN & GILBERT, Synopsis, 241, 1883 ; JORDAN, Bull. U. S. Fish Comm., 1889, 33. 

 Stjualius squamatus, JORDAN & GILBERT, Synopsis, 241, 1883. 



367. LEUCISCUS NIGRESCENS (Girard). 

 (PESCADITO; CHUB OF THE Bio GRANDE.) 



Head 4; depth 4f ; eye about 6. D. 8; A. 8; scales 15-67 (60 to 67)-10; 

 teeth 1, 4-4, 1, or 1, 4-5, 2, usually without grinding surface. Body rather 

 slender, little compressed. Head rather long and pointed. Mouth moder- 

 ate, oblique, terminal, the jaws about equal, the maxillary about reach- 

 ing front of eye. Eye rather small. Scales moderate. Lateral line 

 decurved. Fins large; dorsal behind ventrals, its tip when depressed 

 reaching the posterior base of the anal; pectorals nearly reaching ventrals. 



*This species has been attributed to Lake Tahoe, apparently by error, Rulilus olivaceus having 

 probably been mistaken for it. 



fThis variety is said to differ from the typical form in having the head longer and the scales 

 larger. Scales 12-56-5. 



