CYPEINID^. 55 



belly white; fins black, spotted as in E. lucius. Nearly every writer 

 who has mentioned the Muskallunge has confounded it more or less 

 with U. lucius. Giinther's statement, " body with large rounded whitish 

 spots," applies to JE. lucius, and not at all to U. nohilior, the color in 

 the latter species being gray, with rounded blackish spots. 



I have compared European and American examples of Esox luciuSy 

 and am unable to find any difference whatever. 



DOEYSOMATID^. 



40. DORYSOMA CEPEDIANA, {Le S.) Gill. 

 Subsp. HETEEUEA, (Raf.) Jordan. 



Comparison of specimens of Borysoma from the Wabash Eiver with 

 others from Chesapeake Bay have convinced me that all properly b(?- 

 long to one species, but that our inland form may be recognized as a 

 subspecies, for which the name heterura* may be retained. Var. hete- 

 ura differs chiefly in form ; the back is much less arched, the axis of 

 the body in specimens of about a foot in length being about half nearer 

 the dorsal than the ventral outline. In cepediana, the axis of the body 

 is usually about raidway. The greater arch of the back in cepediana 

 brings the beginning of the dorsal fin nearer snout than base of 

 caudal; in heterura, the dorsal is about midway. The dorsal fila- 

 ment is usually longer in heterura, commonly longer than head ; in 

 cepediana, it is usually shorter than head. The less elevated nape 

 renders the head of heterura rather more slender. 



The name Borysoma may as well be spelled correctly in accordance 

 with its etymology. 



CYPRINIDJ]. 



GENERA OF AMERICAN CYPRINIDiE. 



The following is a semi artificial key to the genera of American Cypri- 

 nidce which I am at present able to recognize. 



Algoma Grd. I refer to Hyhognathus, as one species which I have exam- 

 ined, A. amara has the alimentary canal elongate, and no characters 



* Clupea lieterurus, Eaf., Am. Monthly Mag. Sept. 1818, 354, = Dorosoma notata, Eaf., 

 Ich. Oh. 1820j = Chatoessus elliiMcus, Kiet,, 1838. 



