66 PRELIMINARY REPORT 



with shorter and fainter ones; caudal fin witli a black spot at its 

 base; fins barred with black. Bod}^ elongate, not much com- 

 pressed; head depressed and pointed; mouth small and inferior; 

 snout drawn out, but blunt on the end; premaxillaries not -pro 

 tractile. Head contained 4 to 4f times in the length. Depth 5 to 

 6|. Eye 1^ times the length of the snout, contained 4 times in the 

 head. Dorsal fin XIII to XVII, 12 to 17. Anal 11, 9 to 12. Scales 

 ctenoid, 9-90 to 95-15; present on the cheeks, opercles and back of 

 the neck. Length 6 to 8 inches. A very common darter in the 

 lakes and streams of the northern part of the state. 



A large series of specimens have been taken in the Upper Mis- 

 sissippi and its tributaries (Nat. Hist. Surv., 1893-5); Upper Mis- 

 sissippi and tributaries and St. Louis River and tributaries (Wool- 

 man & Cox, 1894). 



Percina caprod.es zebra (Agassiz). Manitou Darter. 



This variety differs from the typical caprodes in having the back 

 of the neck naked, the cross bars more indistinct and about 20 in 

 number. There is a black caudal spot; dorsal and caudal fins 

 mottled with black. Head contained 4^ times in the length. Depth 

 7. Dorsal fin XV, 14. Anal II, 10. The lateral line contains 

 about 90 scales. 



The only record we have is its occurrence in Lake Superior, from 

 which it was described as Pileoma zebra Agassiz (Lake Superior, 

 308, 1850), and some specimens in the University museum taken 

 from the north shore of Lake Superior (Nat. Hist. Surv., 1878). 

 This variety needs some study. 



Genus HADROPTERUS Agassiz. 



KEY TO THE SPECIES OF HADROPTERUS. 



A. Scales small, about 60 to 70 in the lateral line; cheeks with small 

 scales, larger ones on the opercles; several large, black 



blotches on the sides. aspro, 66 



AA. Scales 50 to 60 in the lateral line; cheeks and opercles with 



some large scales. ....... giiatheri, 67 



Hadropterus aspro (Cope & Jordan). Black-sided Darter. 



Sides with about seven dark spots whose edges join each other; 

 general color yellowish or greenish; upper parts mottled with 

 black. Body elongate, not much compressed except posteriorly, 

 head somewhat elongate; mouth moderate, lower jaw not project- 

 ing, maxillary reaching just beyond the front of the eye. Head con- 



