59 



Abundant; found usually in prairie creeks; not yet taken by us in tributaries of Lake 

 Michigan. Not found in our collections from southward of the latitude of the mouth of the 

 Illinois river, with the exception of one collection from near M t. Cariiiel, and (singularly 

 enoueliMen collections in ilie Illinois spur of the (J/.arlcs, in liie counties of Williamson, 

 Saline, Hardin, Pope, Johnson and I'nion. Taken, in all, from (i8 localities. 



UdtostoinUN )}i(iric((iir ( Lo .Sueui-i. Ilanimer-lu'iul: ll<)<i" Sucker; Ilofr Molly; 

 Mullet: Stone-roller. 



A fish of peculiar appearance; head p>ramidal, body suliconical; eyes very small; mouth 

 large anil sucker like. It is a strong swimmer and is chietiy found upon gravelly riflles, 

 where if feeds upon the bottom. As m the case of many other fishes inhabiting similar 

 situations, the back is crossed with dark bars, which probably serve as a means of protection 

 against tliscovery by wading birds and other enemies. 



Abundant in rapitl, gravelly streams of the Mississippi valley northeastwarrl of a line 

 fron-; the niouth of the Rock river to the mouth of the Kmbarras river. In this section we 

 have eigbt.\-four collections of this species, while southwest of this line we have but four, 

 two of these lying very close to the line, viz. : Little Wabash river at Effingham, Spcjon river 

 at London Mills, Otter creek in Jersey county, and Clear creek. Union county Not found 

 in the few collections which have been made from streams flowing into Lake Michigan. 



Eriiiiijzon siiecttd nldiDKjus (Mitohill). — Chub-sucker; Sweet Sucker. 



The absence of a lateral line serves to distinguish this fish from other suckers. (It should 

 be noted, however, that the young of the next species are without a lateral line also.) The 

 young of this variety are distinguished from adults by the possession of a very black lateral 

 stripe, and may easih' be mistaken for minnows. 



This fish is abundant in the Wabash basin, in the streams tributary to the Ohio river, 

 and in the headwaters of the Kaskaskia; also frequently taken at Havana. It is much less 

 abundant throughout the Illinois valle>-, not having been taken by us between the Illinois 

 and Mississippi rivers. It ajipears in four collections from the Rock river basin. 



Minytrt'ina incJ<t)i<ips (Rafinesque). — Spotted Sucker: Black Sucker. 



Readily recognized by the presence of several longitudinal rows of black dots on the 

 scales of the sides. Latecal line absent in the young and incomplete or broken in adults. 



Abundant in the Wabash basin and in the head waters of the Kaskaskia. One collection 

 from the Saline river at Harrisburg, one from Cedar creek at Simpson, and one from the Big 

 Muddy at Benton. Rareat Havana and Meredosia and in the northern portion of the State. 

 Not taken between the Illinois and Mississippi rivers. This fish apparently prefers the 

 weedy prairie creeks in situations where it is abundant. 



Mo.rostoma (inreolum (Le Sueur). — Common Red-horse: White Sucker: Large- 

 scaled Sucker. 



Scales large; body heavy; head larger than in the next, fiat between the eyes and squarish 

 in cross section; nose ending abruptly. 



Very abundant in streams of all sizes northward; generally found in the black prairie 

 regions. Occurs but six times south of the south line of Shelby county, as follows: Jasper 

 county, N. K.; Fayette county, N.; Wabash countj', E.; Wayne county, W. (2); Saline 

 county, S., and Hardin county, center. 



Moxostoma tnacrDlepidotiun (Le Sueur). — Red-horse. 



Scales large; body more elongate than in the last, tapering from before the dorsal fin for- 

 ward; head rather small, rounded, and bluntly pointed. 

 Common in streams of the northern half of the Slate. 



Placophdnjn.r cltKjnesnci (Le Sueur). — Red horse. (8.5) 



Not certainly distinguishable from .1/. ««rco//i'w without removal and examination of the 

 pharyngeal teeth. Occurs in Illinois, but our collections have not yet been carefully enough 

 examined to determine how frequently it may have been mistaken for .1/. ameolum. 



Family Cypkixid.e (The MI^•No^vs).* 



KEY TO THE GENERA OF ILLINOIS CYPRINID.E. 



(It must be understood that this key is intended only for Illinois representatives of these 

 genera, and in many cases will not apply to those found elsewhere. > 



a. Minnows with intestine of length more than twice that of the body; peritoneum 

 usually black or dark gray. 



b. Intestine spirally wound around the air-bladder. Camposto.ma. 



bb. Intestine not wound around the air-bladder. 



c. Scales small, about 63 to 80 in lateral line. 



d. Body plain silvery Oxyge.nel'M. 



dd. Body striped longitudinally, frequently highly colored Chroso.ml'S. 



cc. Scales larger, about 37 to 4.") in lateral liiie. 



e. Scales not crowded before the dorsal, and not differing much in size from those on 



other parts of the body; breast scaly; first ray of dorsal slender and closely attached 



to second H vhocnathl's. 



ee. Scales small and irregidarly crowded before the dorsal; breast naked; first ray of 

 dorsal J-^ the length of second, not closely attached to it, a membrane interven- 

 ing I'LM EH HALES. 



* The common German carp (Cyprinus carpuA. belonging to the family Cyprinida?, 

 though not native to Illinois waters, is now found in all streartis of the State. It may be 

 recognized by the two long barbels at either side of the mouth, and by the long spine at the 

 front of the dorsal. The large number of rays of the dorsal and the form of the body fre- 

 quently lead to a confusion of this fish with the buffaloes. 



