PERCID^. 49 



Opercle with a sharp flat spiue, usually a smaller oue below it and an 

 obscure one above ; sometimes two or three smaller ones below, often 

 none; the position and number of these spines extremely variable. 

 Cheeks usually closely scaled, the hinder third or loss sometimes nakedc 

 Median furrow on top of head closely scaled. 



Coloration paler and more translucent, the shades less blended than 

 in the Stizostethia; olive-gray above, sides considerably brassy or pale 

 orange, with much black mottling, the black gathered into several defi- 

 nite dark areas, the most distinct of these being opposite the second 

 dorsal ; two others fainter, at each extremity of the spinous dorsal and 

 one at base of caudal. These blotches are irregular and diffuse, but very 

 characteristic. Young specimens are pale orange, with broad black 

 shades. 



Spinous dorsal with two or three rows of round black spots, oue of 

 each row on the membrane between each pair of spines ; no distinct 

 blotch on posterior part of the fin ; a large black blotch at base of pec- 

 torals. Second dorsal with about three rows of irregular dark spots ; 

 caudal yellowish and dusky, almost barred. Fin-rays: — dorsal XII— 1, 17, 

 varying to XIII — 1, 18 ; anal II, 12. Lateral line with 92 to 98 scales. 



Pyloric coeca 4 to 7 ; four of them larger than the rest, of diflerent 

 lengths, all small and shorter than the stomach. The usual number is 

 six, but the two small ones are sometimes one or both absent, sometimes 

 duplicated. Length of adult 10 to 15 inches. 



Habitat. — Great Lake Region, and Upper Mississippi Rivers, also in 

 the Ohio, where it has been introduced from the lakes, through the 

 canals, according to the fishermen. 



The diflerent form and coloration, particularly the markings of the 

 dorsal fin, distinguish this species at once from the Stizostethia. This 

 species has, moreover, always fewer dorsal rays, more scaly cheeks, and 

 a different armature of the operculum. 



The following is a catalogue of the known species of Stizostethium, 

 with references to Dr. Glinther's Catalogue of the Fishes in the British 

 Museum, vol. i : — 



1. Stizostethium (Cynoperca) canadense, {Smith) Jordan. 



Lucioperca canadensis, Guuther, i, p. 75. 

 Lucioperca grisca, Gliuther, i, p. 76. 

 Lucioperca (horea), Giinther, i, p. 501 {d. ».)• 



2. Stizostethium (Stizostethium) vitreum, {MitchiU) Jordan & 

 Copeland. 



Lucioperca amcricana, Gunther, i,p. 74. 

 Bull. N. M. No. 10—4 



