CENTEOPOMUS. 53 



back darker; lateral line usually more or less blackish; spinous dorsal and membrane between second 

 and third anal spines blackish. 



Ilab. Pacific Coasts of Tropical America, entering rivers : 

 Panama 1235. jj_iQ Vauqueria, Ecuador ^. 



Here described from four specimens from Panama, 210-260 mm. in total length. 



Centropomus hrevis is founded on a young example of C. armatus ; and C. atri- 

 dorsalis was described from a small specimen of this species from the Rio Vauqueria, 

 N.W. Ecuador, with the exceptional number of seven branched rays in the anal fin. 



10. Centropomus altus, sp. n. (Tab. Vlll. fig 1.). 



Centroponms armatus (non Gill), Vaill. & Boc. Miss. Sci. Mes., Poiss. p. 34, t. 1 ter, fig. 3 (1874) \ 

 Centropomus ensiftrus (part.), Bouleng. Cat. Fish. i. p. 369 (1895)'. 



Depth of body 3 in the length, length of head 2i. Snout Ih as long as eye, the diameter of which is G in the 

 length of head and equal to the interorhital width. Maxillary extending to below middle of eye, its 

 greatest width | the diameter of eye. Prteorbital acutely serrated posteriorly. Posterior edge of prfe- 

 opercle acutely serrated ; two strong spines at the angle ; lower edge -with onl)' 4 or 5 distinct sernr. 

 Subopercular flap extending a little beyond the vertical from origin of dorsal. 14 gill-rakers, including 

 3 rudiments, on tho lower part of anterior arch. 50-52 scales in a longitudinal series, 7 or 8 between 

 middle of second dorsal and lateral li]ie. Dorsal VIII, I 0-10; spines moderately strong, the third or 

 fourth the longest, a little more than i the length of head. Anal 111 6 ; third spine ^ the length of the 

 second, which is ^ the length of the fish. Pectoral -| the length of head. Venfrals extending a little 

 beyond the vent, which is situated at 4 the distance from base of ventral spine to origin of anal. 

 Caudal peduncle Ij as long as deep. Silvery, back brownish; lateral line not blackish ; vertical fins 

 more or less dusky. 



Hab. Atlantic Coast of Panama, Colon (Boucai'd^). 



The description is based on a single specimen, 170 mm. in total length. Two others, 

 of 85 and 95 mm., agree with it in all essential characters, but have, of course, a shorter 

 snout, larger eye, more elevated spinous dorsal and longer anal spines. The number 

 of scales and fin-rays in these is included in the description. 



C. alius is the Atlantic representative of C. imionensis, from wliich it differs especially 

 in the deeper body, the more strongly armed prseoperculum, and the longer second anal 

 spine, projecting further beyond the third. 



11. Centropomus unionensis. 



Centropomus unionensis, Bocourt, Ann. Sc. Nat. (5) ix. 1868, p. 90'; Vaill. & Boc. Miss. Sc. Mex., 

 Poiss. p. 37, t. 1. fig. 3 (1874) -; Steind. Sitzb. Ak. Wien, Ixxiv. i. 1876, p. 49'; Bouleng. 

 Cat. Fish. i. p. 370 (1895) ' ; Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 1122'; 

 Gilb. & Starks, Mem. Calif. Ac. Sci. iv. 1904, p. 90, t. 13. fig. 27 \ 



Depth of body 3^ in the length, length of head 23. Snout 1| as long as eye, the diameter of which is 7 in 

 the length of head ; interorhital width 6 in the length of head. Maxillary extending to below the middle 

 of eye, its greatest width | the diameter of eye. Prteorbital feebly serrated posteriorly. Posterior edge 

 of prseopercle feebly serrated ; two moderately strong spines at the angle ; lower edge wdth a few serrje. 

 Opercular flap extending slightly beyond the vertical from the origin of dorsal. 14 gill-rakers, including 

 3 rudiments, on the lower part of the anterior arch. 52 scales in a longitudinal series, 7^ between middle 



