268 
BULLETIN OF THE BUREAU OF FISHERIES 
Color of a fresh specimen, 180 millimeter long, grayish black above; sides 
silvery; under parts pale silvery; scales on sides with dark edges; an indistinct 
dark blotch at base of caudal; first dorsal with dark spines and yellow interradial 
membranes; second dorsal greenish, with a broad translucent margin; caudal 
and pectorals plain translucent; the latter dark at base; anal and ventrals mostly 
yellowish; iris golden. A smaller specimen, 82 millimeters long, lighter, the black 
on margins of scales on sides not continuous, forming specks; caudal spot more 
distinct. 
Two specimens of this species, respectively 82 and 180 millimeters in length 
were taken. It is improbable that this fish is as scarce as indicated by the few 
specimens secured, for it appears to be well known to the native fishermen, according 
to whom the species occurs in streams in several localities where it was not taken 
by us. One of our specimens was taken in a deep rocky place in the Rio del Desague, 
a short distance below Lake Guija, of which this river is the outlet. The smaller 
specimen was taken in quiet shallow water on a sandy bottom in the Rio Lempa at 
San Marcos. 
According to the fishermen at Lake Guija the "Tepemechin" spawns in June. 
The eggs are much sought and considered a great delicacy. One fish is said to 
produce a quantit}^ of eggs, which in bulk is greater than that of the entire fish. 
The species, according to native fishermen, reaches a length of about 250 millimeters. 
This species, as here understood, ranges from southern Mexico to Panama, 
occurring on both slopes of Central America and Panama. It is also known from 
the West Indies. The specimens at hand are from the Rio del Desague, near 
Lake Guija, and from the Rio Lempa at San Marcos. 
Family IX. CENTROPOMIDi€ 
The Robalos 
Body moderately elongate, compressed; head long, somewhat depressed 
above; mouth large, protractile; lower jaw projecting; teeth in villiform bands 
on jaws, vomer, and palatines; preopercle and supraclavicle serrate; preopercle 
with a ridge, usually bearing 2 spines; opercle without spines, produced as a flap; 
lateral line more or less arched, continued to end of caudal fin; scales small or of 
moderate size, ctenoid; two separate dorsal fins; the first consisting of 7 or 8 
spines; second dorsal with 1 spine and 8 to 11 branched rays; caudal fin forked; 
anal short, with 3 spines and 6 or 7 branched rays; ventral fins inserted behind 
base of pectorals, with I, 5 rays; pectoral fins symmetrical; air bladder large, 
with or without appendages. 
All the species of this family are American and are included in one genus. 
13. Genus CENTROPOMUS Lacepede 
CentTopomus LaoSpede, Hist. Nat. Poiss., IV, 1803, 248 (type Scisena undecimalis Blooh). 
Oxylahrax Bleeker, Arch. Need. Sci. Nat., XI, 1876, 264 (type Scisena undecimalis Bloch). 
MacToccphalus Bleeker, Arch. Neerl. Sci. Nat., XI, 1876, 336 (type Scisena undecimalis Bloch). 
The characters of the genus are included in the family description. The 
species of this genus are game fishes. Some of them reach a large size, and the 
