MICROPTERUS. 35 
With the exception of Micropterus salmonoides, a characteristic feature is the 
prolongation of the operculum as a blackish membranous flap. 
In view of the recent work on this group of Boulenger and Jordan and Evermann, 
a full account would be superfluous. I have, however, examined the specimens in the 
British Museum, and have prepared a synopsis of the Mexican species. 
Synopsis of the Mexican Species of Centrarchide. 
I. Supramaxillary bone well developed. 
Dorsal X 12-13. Anal III 10-11. Scales 65-70 an Depth of 
body 8to 3$inthelength . . . . 2... . . . 
Dorsal X-XI 10-11. Anal III 8-9. Scales 45-55 =1,. Depth of 
body 2to 2hinthe length . . . . . . . 1 1 « « . Apomotis cyanellus. 
Micropterus salmonoides. 
IL. Supramaxillary bone absent or rudimentary. 
A. Pectoral much shorter than the head, not extending to above the anal. Dorsal X 10-12. 
Anal IIT 8-10. 
Scales 36-45 ,>°. Depth of body 13-24 in the length. 
14-16° 
Longest dorsal spine about } the length of head. . . . . Lepomis megalotis. 
Scales 35-38 ¢:. Depth of body 23 in the length. Longest 
dorsal spine nearly } the length of head . . . . . . « L. haplognathus. 
B. Pectoral as long as or a little longer than the head, extending to above the anal spines. 
Dorsal X 11-12. Anal TIT 11-12. 
Scales 48-52 Fw ee ee ee ee. Eupomotis pallidus. 
Seales 34-40 27 2. 2 ee ee ee ee KL heros. 
13-15 
1. MICROPTERUS, Lacep., 1802. 
Micropterus, Bouleng. Cat. Fish. i. p. 14 (1895). 
1. Micropterus salmonoides, Lacep., 1802. 
Micropterus salmonoides, Bouleng. Cat. Fish. i. p. 16 (1895); Jord. & Everm. Bull. U.S. Nat. 
Mus. xlvii. 1896, p. 1012. 
Hab. Nort America, east of the Rocky Mountains, from the Red River and the Great 
Lakes to Tamaulipas. 
‘The “‘Large-mouthed Black Bass” is at once distinguished from other Mexican 
Centrarchide by the larger mouth, the more elongate body, and the absence of a 
membranous prolongation of the operculum. 
