DR. GUNTHER ON THE FISHES OF CENTRAL AMERICA. 461 
176. Heros rrimacunatus. (Plate LX XVI.) 
D. i. ASS. Le lat. 81. L. transv. 5/14. 
Allied to H. salvini. Fold of the lower lip continuous in the middle; scales of the 
cheek in five series. Lower jaw prominent. Preorbital as wide as the orbit, with the 
antero-inferior margin concave. The length of the twelfth dorsal spine is rather less 
than one-third of that of the head. Dark greenish olive, with three black spots; the 
first above the origin of the lateral line, the second in the middle of the side, and the 
third above the end of the lateral line. Fins black. 
Three adult examples, from 8 to 11 inches long, and one of 23 inches, were collected 
by Mr. Salvin at Chiapam and Huamuchal. 
Description —The height of the body is contained twice in the total length (without 
caudal), the length of the head twice and two-thirds. Head nearly as high as long; 
snout rather pointed, much longer than the eye, with the cleft of the mouth very 
oblique, and the lower jaw prominent; the maxillary extends nearly to the vertical 
from the front margin of the orbit. Preorbital as wide as the orbit, with the antero- 
inferior margin concave. The width of the orbit is one-fifth of the length of the head, 
but only two-thirds of that of the interorbital space. The eye is situated immediately 
below the concavity of the upper profile of the head, and is very slightly nearer to the 
tip of the snout than to the opercular margin. Opercles scaly; suboperculum with two 
series of scales. The vertical fins are scaly at the base. Dorsal spines of ‘moderate 
strength and length, the twelfth being rather less than one-third of the length of the 
head. The points of the soft dorsal and anal extend beyond the middle of the caudal. 
Caudal much rounded. ‘The distance between the caudal and the dorsal is considerably 
less than the depth of the free portion of the tail. Pectoral much shorter than the 
head, extending only to the second anal spine; ventrals with the outer ray produced. 
The distance between the vent and the root of the ventrals is nearly half the length of 
the head. The coloration of the young example is exactly the same as that of the adult. 
177. Heros pov. (Plate LX XIII. fig. 4.) 
Ginth. Proc. Zool. Soc. 1864, p. 154. 
D. a A. — L. lat. 35. L. transy. 4. 
The fold of the lower lip is continuous in the middle. The height of the body is 
contained thrice in the total length (without caudal); the length of the head twice and 
three-fifths. Snout pointed, with the lower jaw very prominent. Preorbital with the 
antero-inferior margin but slightly concave, its greatest width being three-fourths of 
that of the orbit. Both jaws with a pair of fangs, those of the upper pair being close 
together in the middle of the jaw, whilst the lower are separate. Scales on the cheek 
small, rather irregularly arranged, in about eight series. The first dorsal spine is 
inserted behind the vertical from the upper end of the gill-opening. Dorsal and anal 
