FISHES OF THE MISSOURI RIVER BASIN. 397 



of the body. Girard's types of //. evansi came from Fort Pierre, Nebr., and 

 it' identical with placitux the name ercmsi has precedence, and the form may 

 stand as Hybognathus nudhale evansi Girard. 



41. Hybognathus argyrite Girard. Milk River (as //. argyritis type, Girard, 



1856 and 1858, and Suckley, 1860). This is a doubtful species, probably 

 identical with II. evansi. 



42. Hybognathus nubilum (Forbes). Piuey Creek, Texas County, Mo. (Call, 1887) ; 



Jones Creek and Marais River, Dixon, Mo. ; Little Piney River at Arling- 

 ton and Newburg, Mo. ; Osage Fork, Marshtield, Mo. ; Lock Fork, Mansfield, 

 Mo.; Niangua River, Marshtield, Mo.; Sac River, Springfield, Mo. (Meek, 

 1891). Obtained by us at the following places: Floyd River, Sioux City; 

 Bazile Creek, Niobrara; Verdigris Creek, Verdigris; Elkhorn River, Nor- 

 folk Junction; Norfolk Creek, Norfolk; pond at Long Pine; Ponca Creek, 

 Niobrara; canal at Niobrara; pond at Creighton; Niobrara River north of 

 Long Pine; Emanuel Creek, Springfield; Choteau Creek, Springfield; Crow 

 Creek, Chamberlain; White River, Chamberlain; Platte River, Casper; 

 Powder River, Arvada. 



A very large series of specimens of Hybognathus was collected, but we find 

 it extremely difficult to decide just how many and what species are repre- 

 sented. For the present it seems best to recognize nubila, argyrite nuchalis, 

 and var. evansi. The range of variation in each is great. II. nubila is the 

 more common form in eastern Nebraska and southwestern South Dakota, 

 and is distinguished by the much larger eye (less than 4 in head), the larger 

 mouth, more pointed snout, and the plumbeous lateral stripe: ordinarily 

 this lateral stripe is quite distinct and characteristic. This species is found 

 chiefly in the clearer, colder streams. Typical nuchale was found in Salt 

 Creek at Havelock, and Fremont, Nebr., and by Dr. Gilbert at several 

 places in Kansas. It is not unlikely that some of the specimens from middle 

 Nebraska, that we have identified with evansi, are really nuchale. The two 

 forms are very close and can be distinguished with difficulty. We identify 

 with evansi that form with a small eye (4J to 5! in head), short, blunt snout, 

 small mouth, and very pale coloration; it is perhaps more slender, also. 

 The specimens of H. nuchale have a somewhat larger eye (about 4 in head), 

 rather larger, sharper snout, and slightly darker coloration, in these respects 

 approaching nubilum. 



43. Pimephales promelas Rafinesque. Fat-head; Black-head Minnow. Yellow- 



stone River (as P. fasciatus type, Girard, 1856) ; Yellowstone River and Milk 

 River (as P. fasciatus, Girard, 1858); Milk River (as P. fasciatus, Suckley, 

 1860); Kansas River near Fort Riley (Cope, 1865); Missouri River near St. 

 Joseph (as Coliscus parietalis type, Cope, 1871); Battle Creek, S. Dak. (as 

 Hyborhynchus nigellus, Cope, 1879); Ward Creek, Menoken, Kans. ; Shun- 

 ganunga Creek and Kansas River, Topeka; Ellis, Kans. (as P. confertus, 

 Gilbert, 1884); Hundred and Two River at Bedford, Iowa, and Maryville, 

 Mo. (Jordan & Meek, 1885); Kansas River (Graham, 1885); Kansas River 

 at Topeka, and small streams in Shawnee, Wabaunsee, and Ellis Counties, 

 Kans. (Cragin, 1885a); Blacksmith Creek, Shawnee County, Kans. (Gilbert, 

 1885) ; Solomon River, Beloit, Kans. ; north fork of Solomon River at Kirwin 

 and Lenora, Kans.; Saline River, Wakeeney, Kans.; Smoky Hill River, 

 Wallace, Kans. (as /'. promelas confertus, Hay, 1887); north fork of Solomon 

 River at Logan, Kans., and Middle Beaver Creek, Smith County, Kans. (Gil- 

 bert, 1889); Silver Lake, Iowa; Soldier River, Charter Oak, Iowa; Boyer 

 River, Arion, Iowa (Meek, 1892) ; Blue River, Crete, Nebr. ; Platte and Elk- 

 horn rivers, Fremont, Nebr. ; Salt Creek, Lincoln, Nebr. ; Floyd River at 

 Sioux City and Lemars, Iowa (Meek, 1894) ; Dakota River at Lamoure 

 (Woolman, 1896) ; Dover, S. Dak. (Butler, 1896). 



