DIPLESION 293 



knobbed at extremities; separation of ventrals less than their width at base. 

 Scales 6-8, 57-61, 7-9 [10 or 11]; lateral line nearly straight and usually com- 

 plete, 1 or 2 pores occasionally lacking; cheeks naked or with a few more or less 

 embedded scales; opercles and nape scaled; breast naked; belly with ordinary 

 scales. 



This beautiful and peculiar species, distinguishable at a 

 glance by its remarkable head, large prominent eyes, and small 

 inferior mouth, " giving it a decidedly frog-like profile," and by 

 the green or olive zigzag markings on the back, is, in its breeding 

 dress, one of the most beautiful of all fresh-water fishes. "The 

 dorsal fins become bright grass-green, with a scarlet band at 

 the base; the broad anal has a tinge of the deepest emerald; 

 while every spot and line upon the side has turned from an 

 undefined olive to a deep, rich green, scarcely found elsewhere 

 in the animal world except on the backs of frogs. The same 

 tint flashes out on the branching rays of the caudal fin, and may 

 be faintly seen struggling through the white on the belly. The 

 blotches nearest the middle of the back become jet-black, and 

 thickly sprinkled everywhere are little shiny spots of a clear 

 bronze-orange. "* 



This darter has an almost inexplicable distribution in 

 Illinois, if we may judge by our collections of it. Taken by us 

 in thirty-six localities on the smaller streams of the Wabash 

 system in this state, it has not once occurred elsewheref in all 

 our sixteen hundred collections, although it has been once 

 taken from the Des Plaines at Joliet, by J. H. Ferris, as reported 

 by Fowler in 19064 Its general distribution is not such as to 

 suggest so limited a range in Illinois, occurring, as it does, from 

 Lakes Ontario and Erie to Pennsylvania, North Carolina, and 

 the lower Alabama basin, and thence to South Dakota, Kansas, 

 and Missouri, and the Red River in Arkansas. It is generally 

 distributed throughout Indiana, as shown by the details of the 

 list of Professor Hay, who reports it as abundant in all suitable 

 streams. This is one of the groups of species occurring, in Illi- 

 nois, only or mainly in the Wabash drainage, specially discussed 

 in our introductory chapter on geographical distribution. It is 

 found in swift water, oftenest on rocky ripples where there is a 



* Jordan and Copeland, American Naturalist, Vol. X., p. 339. 



f The indication of its presence at Chicago given on Map VII. of an article on the local 

 distribution of darters (Bull. 111. Stats Lab. Nat. Hist., Vol. VII., Art. VIII.) published by the 

 senior author in Apiil, 1907, is due to a clerical error in transferring a record based on the preg- 

 servation of specimens from collections on exhibition at the World's Fair in 1893. 



t "Some New and Little Known Percoid Fishes." Proc. Acad. Nat. Sci. Phila., Dec., 

 1906, p. 522. 



