CENTEOPOMUS. 45 



1. CENTEOPOMUS, Lacep., 1802. 



Centropomus, Bouleng. Cat. Fish. i. p. 366 (1895); Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 

 1896, p. 1117. 



Eody compressed; scales small or of moderate size, finely ctenoid. Lateral line nearly straight, continued to 

 the end of the caudal fin. Mouth rather large, protractile ; maxillary exposed ; lower jaw projecting ; 

 bands of villiform teeth with obtuse crowns in jaws and on vomer and palatines. Praeorbital and supra- 

 claviclo serrated. Prieoperculum with a ridgo parallel to its free edge, bearing 1 or 2 spines at the angle ; 

 edge of priBoperculum serrated, with enlarged serrte or spines at the angle ; suboperculum produced into 

 a long flap. Two dorsals, with VIII, I 9-11 rays; the first spine very small, the second short, the third 

 or fourth the longest; anal short, with III 6-7 rays ; caudal forked; pectoral asymmetrical, obtusely 

 pointed ; ventrals behind base of pectorals, with I 5 rays ; a scaly process at the base of the spine of each 

 ventral fin. 



Ilab. Coasts and rivers of Tropical America. 



I am glad to have the opportunity of attempting a revision of this interesting and 

 difficult genus, and, after examination of all the specimens in the British Museum 

 collection, I have arrived at the conclusion that none of the species occur on both the 

 Pacific and Atlantic Coasts. 



Although marine, nearly all the species are known to ascend rivers for considerable 

 distances, so that they must be included in the fresh-water fauna. 



Synopsis of the Species. 



I. Anal with 7 branched rays ; opercular flap not extending to the vertical from origin of dorsal ■, 



second and third anal spines of equal length, or the second slightly the shorter. 

 66-72 scales in a longitudinal series, 8^ between middle of second dorsal and 



lateral line 1. pectinatu!i. 



56-65 scales in a longitudinal series, 6^ to 7\ between middle of second dorsal 



and lateral line 2- medius. 



II. Anal with 6 (exceptionally 7) branched rays. 



A. Opercular flap extending to the vertical from origin of dorsal ; 75-88 scales 



in a longitudinal series ; second anal spine a little longer than the third . 3. parallelus. 



B. Opercular flap not extending to the vertical from origin of dorsal ; 65-80 scales in a 



longitudinal series. 



1. Third dorsal spine usually the longest, about \ the length of head; 65-75 



scales in a longitudinal series, 7itoSi between middle of second dorsal 

 and lateral line. 

 Second anal spine usually slightly longer than the third, -}-! the length 

 of the fish (,l- in specimens of 295-330 mm.) ; vent at more than § 

 of the distance from base of ventral spine to origin of anal. ... 4. undecimulis. 

 Second anal spine not longer than the third, nearly I- the length of the 

 fish (in specimens of 320-345 mm.) ; vent at less than j? of the 

 distance from base of ventral spine to origin of anal 5. viridis. 



2. Third or fourth dorsal spine the longest, ^ the length of head ; 73-80 



scales in a longitudinal series, 9 or 10 between middle of second dorsal 



and lateralbne ; second anal spine not longer than the third . ... 6. Hiffrescens. 



