DR. GUNTHER ON THE FISHES OF CENTRAL AMERICA. 407 
length (without caudal), the length of the head twice and four-fifths, Preorbital 
finely serrated ; suboperculum produced into a flap, which does not extend to the 
vertical from the origin of the dorsal fin. The intermaxillary extends somewhat beyond 
the anterior margin of the orbit. Dorsal spines strong; the third is longer than the 
fourth, and half as long as the head. The second anal spine long, but a little shorter 
than the third, and equal in length to the distance between the extremity of the upper 
jaw and the preopercular margin. The length of the ventral fin is much more than 
one-half of its distance from the anal fin. Lateral line black. 
Two specimens, 13 inches long, from Chiapam. 
3. CENTROPOMUS NIGRESCENS. 
Ginth. Proc. Zool. Soc. 1864, p. 144. 
D, 8|7, A. >. .'L. Jat. 70 
Ten longitudinal series of scales between the origin of the second dorsal fin and the 
lateral line. The height of the body is contained four times and a half in the total 
length (without caudal), the length of the head twice and four-fifths. Preorbital not 
serrated; suboperculum produced into a short flap, which does not extend to the 
vertical from the origin of the dorsal fin. The intermaxillary extends a little beyond 
the middle of the orbit. Dorsal spines rather feeble; the third and fourth are equal 
in length, two-fifths of the length of the head. The second and third anal spines also 
are equal in length, and not longer than the dorsal spines mentioned. The length of 
the ventral fin is scarcely more than one-half of the distance of its base from the anal. 
Air-bladder without appendages anteriorly. Silvery; upper parts and fins blackish; 
lateral line black. 
One specimen, 14 inches long, from Chiapam. 
This species is allied to C. appendiculatus (Poey), but differs externally in its con- 
siderably more feeble and shorter fin-spines. 
4, CENTROPOMUS PARALLELUS. 
Poey, Mem. Cuba, ii. p. 120. 
D. 8|7 A.3. L, lat. 85-90. 
Twelve longitudinal series of scales between the origin of the second dorsal fin and 
the lateral line. The height of the body is contained thrice and three-fourths in the 
total length (without caudal), the length of the head twice and a half. Preorbital 
distinctly serrated ; suboperculum produced into a flap, which extends to the vertical 
from the origin of the dorsal fin. The intermaxillary extends a little beyond the 
middle of the orbit. Dorsal spines rather feeble ; the third is the longest, half as long 
as the head. The second anal spine is exceedingly strong, longer than the third and the 
third dorsal spine. The length of the ventral fin is considerably more than one-half of 
