XOTROPIS 



141 



of lower margin of pupil; maxillary reaching front of orbit; lower jaw 

 slightlv 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 S or 6 

 (usuallv S), 35-3 7, 3; 13 to 15 in front of dorsal tin; lateral line complete, 

 somewhat decurved anteriorly. 



.nwui*- 1, ' > ■ "* 





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 1 7 localities, the only 

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

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

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

 cock county. Its general 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) 



DeWitl Clinton, 1824, Ann Lye. Nat. Hist. X. V., I, 4<> (Clupea). 

 G., VII, 251 (Leuciscusi; M. V., 57; ] & E., I. 26'); X., 46 (Hybopsis); |., 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 serve to separate it from the 

 other larger and paler species of Illinois Cyprinida. Length 4 t<> <> 

 inches; body moderately robust, nut much elongate, considerably com- 

 pressed, the sides vertical at their middle; depth -1 to 4.5 in length; 



