MICEOPTEEUS. 35 



With the exception of Micropterns sahnonoides, 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 Centrarchidae. 



I. Supramaxillarji bone well developed. 



Dorsal X 12-13. Anal III 10-11. Scales 65-70 J:',. Depth of 



body 3 to 3^ in the length Micropterus sahnonoides. 



Dorsal X-XI 10-11. Anal III 8-9. Scales 45-55 -^^. Depth of 



body 2 to 2^ in the length Apomotis cyanellus. 



II. Supramaxillary bone absent or rudimentary. 



A. Pectoral much shorter than the lieadj not extending to above the anal. Dorsal X 10-12. 

 Anal III 8-10. 



5-6 



Scales 36-45 jg^. Depth of body 1|-2J- in the length. 



Longest dorsal spine about -J- the length of head Lepomis megalotis. 



Scales 35-38 j|^.. Depth of body 2^ in the length. Longest 



dorsal spine nearly \ the length of head L. hajAognathus . 



B. Pectoral as long as or a little longer than the head, extending to above the anal spines. 

 Dorsal X 11-12. Anal III 11-12. 



Scales 43-52 ^^~ Euponiolis pallidus. 



Scales 34-40 ,.^f. E. heros. 



1. MICROPTERUS, Lacep., 1802. 

 Micropterus, Bouleng. Cat, Fish. i. p. 14 (1895). 



1. Micropterus sahnonoides, Lacep., 1802. 



Micropterus salmonoides, Bouleng. Cat. Fish. i. p. 16 (1895); Jord. & Everm. Bull. U.S. Nat. 



Mus. xlvii. 1896, p. 1012. 

 Bab. North 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 

 Centrarchidae by the larger mouth, the more elongate body, and the absence of a 

 membranous prolongation of the operculum. 



F 2 



