212 U.S. NATIONAL MUSEUM BULLETIN 2 82 



rakers on the left arch and eight on the right. The general color of 

 this specimen is a mottled brown. When first preserved, the individual 

 was light reddish orange with dark mottling and was tentatively 

 identified as Noturus miurus. 



In the largest specimen, side of body and peduncle mottled medium 

 brown, darkest below dorsal fin and over air bladder; upper surface 

 of head and upper barbels mottled dark brown, side of head lighter; 

 lower surface of head and abdomen pale yellowish with numerous 

 small chromatophores which are most concentrated just in front of 

 pelvic fins and on the chin in front of barbels; lips and lower barbels 

 dusky; pelvic fin pale yellowish, upper and lower surfaces with 

 scattered chromatophores which are most concentrated near the base; 

 pectoral fin dusky, especially near the spine, edge pale; dorsal fin 

 with outer parts of rays brownish black, suggesting the black blotch 

 of A^. miurus, middle of fin yellowish, base dusky; a semblance of a 

 basidorsal dark spot, and an obovate round yellowish spot at the 

 base of the last three dorsal rays; anterior and posterior end of adipose 

 fin yellowish, with a wide, medial, dark brown blotch that extends 

 to margin; area between dorsal and adipose fin dark brown; caudal fin 

 grayish brown, margin of rays yellowish, and a submarginal brownish 

 black band encircling the fin; anal fin yellowish brown with a dark 

 band on the ends of rays of anterior three-fourths of fin. 



In the smaUer Michigan specimen, belly and lower surface pale, 

 with little scattered pigment; upper side and dorsal surface dark 

 gray; lower half of caudal peduncle light gray; caudal fin with a 

 moderately dark submarginal band; anterior lower procurrent 

 caudal rays pale; anal fin with a prominent dark gray submarginal 

 band; adipose fin dark gray, with a darker, definite obtuse blotch; 

 dorsal fin gray, with tips of the first rays blackened; pectoral fins 

 with blackish distal blotches. 



The Indiana specimen (USNM 199583) has 34 vertebrae of which 

 12 are anterior to the anal fin, 7 hypurals without fusion, and 1 epural. 

 There are about two small, short serrae near the posterior base of 

 the pectoral spine. Its color is generally brownish, with darker traces 

 of the miurus pattern superimposed, most prominent of which is the 

 dark gray adipose blotch of miurus. The New York specimen is also 

 brownish in color with miurus blotching. 



Discussion. — That these specimens are correctly identified as 

 hybrids between Noturus gyrinus and Noturus miurus is indicated by 

 their color pattern and general intermediate morphology. The blotches 

 of the dorsal surface although nearly obscured, and the darkened 

 fin margins when present suggest a form of the subgenus Rabida; 

 the general darkening of the body suggests one of the nearly unicolored 

 species of Noturus. 



