CENTROPOMUS. 53 
back darker; lateral line usually more or less blackish; spinous dorsal and membrane between second 
and third anal spines blackish. 
Hab. Pacific Coasts of Tropical America, entering rivers: 
Panama!?35; Rio Vauqueria, Ecuador °. 
Here described from four specimens from Panama, 210-260 mm. in total length. 
Centropomus brevis 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. VIII. fig 1.). 
Centropomus armatus (non Gill), Vaill. & Boc. Miss. Sci. Mex., Poiss. p. 34, t. 1 ter, fig. 3 (1874)*. 
Centropomus ensiferus (part.), Bouleng. Cat. Fish. i. p. 369 (1895)*. 
Depth of body 3 in the length, length of head 23. Snout 14 as long as eye, the diameter of which is 6 in the 
length of head and equal to the interorbital width. Maxillary extending to below middle of eye, its 
greatest width 5 the diameter of eye. Preorbital acutely serrated posteriorly. Posterior edge of pre- 
opercle acutely serrated; two strong spines at the angle; lower edge with only 4 or 5 distinct serre. 
Subopercular flap extending a little beyond the vertical from origin of dorsal. 14 gill-rakers, including 
3 rudiments, on the lower part of anterior arch. 50-52 scales in a longitudinal series, 7 or 8 between 
middle of second dorsal and lateral line. Dorsal VIII, I 9-10; spines moderately strong, the third or 
fourth the longest, a little more than 2 the length of head. Anal III 6; third spine 4 the length of the 
second, which is ¢ the length of the fish. Pectoral 2 the length of head. Ventrals extending a little 
beyond the vent, which is situated at 2 the distance from base of ventral spine to origin of anal. 
Caudal peduncle 13 as long as deep. Silvery, back brownish ; lateral line not blackish ; vertical fins 
more or less dusky. 
Hab. Atlantic Coast of Panama, Colon (Boucard 2). 
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. altus is the Atlantic representative of C. wnionensts, from which it differs especially 
in the deeper body, the more strongly armed preoperculum, 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. 8 (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 33 in the length, length of head 28. Snout 1? as long as eye, the diameter of which is 7 in 
the length of head ; interorbital width 6 in the length of head. Maxillary extending to below the middle 
of eye, its greatest width } the diameter of eye. Preorbital feebly serrated posteriorly. Posterior edge 
of preopercle feebly serrated; two moderately strong spines at the angle ; lower edge with a few serre. 
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, 74 between middle 
® 
