396 REPORT OP COMMISSIONER OP FISH AND FISHERIES. 



Closely related to Chrosomus erythrogaster. Head 3§; depth 4£; eye 3|; 

 snout 4J-; D. 8; A. 8; scales about 80, 24 in cross series. Teeth 4-4, hooked, 

 and with a slight grinding surface. Body moderately stout, head heavy, 

 caudal peduncle shorter than in related species. Eye moderate, interorbital 

 width 3 in head ; mouth small and oblique, maxillary short, not nearly reach- 

 ing vertical at front of eye, its length 1^ in eye; lower jaw projecting. Fins 

 moderate; height of dorsal 1^ in head, its origin behind the base of the 

 ventrals a distance greater than length of snout; anal similar to dorsal; 

 pectorals short, 1£ in head; ventrals very short, not reaching anal. Color as 

 in C. erythrogaster, except that the back is darker and the upper dark line is 

 continuous and not broken up into spots; the lower black line is also more 

 distinct. Besides the 11 specimens obtained in Crow Creek we have two 

 from a pond at Niobrara and one from Miunechaduza Creek at Valentine, 

 Nebr. The specimens from Battle Creek, S. Dak., referred by Professor Cope 

 (1879) to Chrosomus sp., probably belong to this species. 



39. Hybognathus nuchale Agassiz. Ward Creek, Menoken, Ivans., and Kan- 



sas River, Topeka (Gilbert, 1884) ; Hundred and Two River at Bedford, 

 Iowa, and Maryville, Mo. ; Missouri River, St. Joseph (Jordan &, Meek, 

 1885); Kansas River, Ward Creek, and Fort Riley (Cragin, 1885a); Piney 

 Creek, Texas County, Mo. (Call, 1887) ; Smoky Hill River, Wallace, Kans. 

 (Hay, 1887); north fork of Solomon River, Logan, Kans. (Gilbert, 1889); 

 Missouri River, Iowa; Big Sioux River, Sioux City, Iowa; Soldier River, 

 Charter Oak, Iowa (Meek, 1892) ; Platte and Elkhorn rivers, Fremont, Nebr.; 

 Salt Creek, Lincoln, Nebr. ; Floyd River at Sioux City and Lemars, Iowa 

 (Meek, 1894); Dakota River at Jamestown (Woolman, 1896). 



40. Hybognathus nuchale evansi (Girard). Missouri River at Fort Pierre, Nebr. 



(as H. evansi type, Girard, 1856) ; Fort Pierre and Sweetwater River (Girard, 

 1858); upper Platte River (Cope, 1864a); Kansas River near Fort Riley 

 (Cope, 1865); Battle Creek, S. Dak. (Cope, 1879); Kansas River and other 

 branches of the Missouri (as H. placita, Graham, 1885) ; South Platte River, 

 Denver (as H. nuchalis placita, Jordan, 1891); Cottonwood, Hat, and Middle 

 creeks, and south fork of Cheyenne and Belle Fourche rivers, Black Hills 

 (as H. nuchalis placita, Evermann, 1893); Poplar River, Poplar, Mont, (as 

 H. placita, Eigenmann, 1894). 



Our collections contain specimens from the following localities: Ponca 

 Creek near Niobrara; Bazile Creek, Niobrara; Platte River, Grand Island; 

 Wood Creek, Grand Island ; Middle Loup River, Dunning ; Niobrara River 

 north of Long Pine; South Loup River, Ravenna; Mud Creek, Ravenna; 

 Platte River, Fremont ; White River, Chadron ; Lone Tree Creek, Chadrou ; 

 Choteau Creek, Springfield; Cheyenne River near Hot Springs; Hat Creek, 

 Ardmore; Cottonwood Creek, Edgemont; Crow Creek, Chamberlain; 

 Emanuel Creek, Springfield; Belle Fourche River, Belle Fourche; Chey- 

 enne River, Edgemont; White River, Chamberlain; Middle Creek, Belle 

 Fourche; Powder River, Arvada; Beaver Creek, Newcastle; Platte River, 

 Douglas; Platte River, Casper. 



The following notes are from a specimen 5 inches long, from Belle Fourche 

 River: Head 5; depth 4J-; eye 5; snout 3£; D. i, 8; A. i, 9; scales 6-40-7, 18 

 before dorsal; mouth small, slightly oblique, lower jaw included; maxillary 

 short, not reaching eye. Origin of dorsal a little in front of veutral, and 

 nearer snout than base of caudal ; height of dorsal nearly equal to length of 

 head; interorbital width equal to length of snout to middle of pupil. In a 

 specimen from Ravenna the scales count 6-43-5, 16 before the dorsal. There 

 is considerable variation in the snout, it being much more blunt in some 

 than in others, those from Ardmore being especially blunt. This minnow 

 seems to be peculiarly liable to be affected by parasites, a considerable 

 percentage of the specimens from Belle Fourche, Ravenna, and Cheyenne 

 Falls showing psorosperms embedded among the scales over different parts 



