XOTROPIS 141 



of lower margin of pupil; maxillar\^ reaching front of orbit; lower jaw 

 slightly shorter than upper; isthmus less than pupil. Teeth 1, 4-4, 1; 

 intestine about 1.15 times length of head and body; peritoneum a very 

 dark brown to almost solid black. Dorsal fin with 8 rays, inserted a 

 little behind ventrals, about equidistant between muzzle and base of 

 caudal; longest dorsal ray usually a little less than head, 1 to 1.2; anal 

 rays 8 (occasionally 7) ; pectorals § to | to ventrals, 1.1 to 1.3 in head; 

 ventrals to vent, not reaching anal in any of our specimens. Scales 5 or 6 

 (usually 5), 35-37, 3; 13 to 15 in front of dorsal fin; lateral line complete, 

 somewhat decurved anteriorlv. 



Fig. 35 



This species, rather rare in Illinois, is closely limited in the main 

 to the tributaries of the Wabash in the eastern part of the state, 

 from which it is recorded in our collections at 17 localities, the only- 

 other places of its occurrence in this state being Cedar Lake, in 

 northeastern Illinois, Mazon creek, a branch of the Illinois River 

 near its origin, and a small hlufi stream of the Mississippi, in Han- 

 cock county. Its genera i range is from the Lake Erie basin and 

 the Ohio River westward to Arkansas and ^Missouri. 



Females with fully developed eggs, and breeding males with 

 muzzle and chin tuberculate, have been taken by us in the latter 

 part of May. 



NOTROPIS HUDSONIUS (DeWitt Clinton) 

 (spot-tailed minnow) 



DeWitt Clinton, 1824, Ann. Lye. Xat. Hist. \. Y., I, 49 (Clupea'). 



G., VII, 251 (Leuciscus); M. V., 57; J. & E., I, 269; N., 46 (Hybopsis) ; J., 56 (Al- 

 burnops); F. F., I. 6, 82 (Hybopsis); F., 77; L., 17. 



The usually large and conspicuous black caudal spot of this minnow, 

 rarely absent in western specimens of the species, will commonly serve to 

 call attention to it when found, and will sen^e to separate it from the 

 other larger and paler species of Illinois Cyprinidcz. Length 4 to 6 

 inches; body moderately robust, not much elongate, considerably com- 

 pressed, the sides vertical at their middle; depth 4 to 4.5 in length; 



