444 DR. GUNTHER ON THE FISHES OF CENTRAL AMERICA. 
right one; the preorbital tapers posteriorly, has the anterior margin finely serrated, 
and-covers the maxillary, so that only a very narrow portion of it is visible on the side 
of the snout. Eyes hidden anteriorly and posteriorly by a broad adipose membrane. 
Nostrils rather distant from each other, the posterior situated nearer to the orbit than 
to the extremity of the snout. The space of the chin, between the mandibles and the 
interopercula, is elongate cuneiform. The second dorsal and the anal are enveloped 
in small scales. There are twenty-three scales between the snout and the anterior 
dorsal. The second dorsal spine is longer than the first, and more than half as long as 
the head, The tenth, eleventh, and twenty-fifth scales of the lateral line correspond to 
the extremity of the pectoral fin and to the origins of the two dorsal fins. The root of 
the pectoral is above the middle of the body; and the ventral is inserted somewhat 
nearer to the pectoral than to the spinous dorsal; pectoral shorter than the head ; 
caudal deeply emarginate. Silvery, axil of the pectoral blackish. 
We have received examples of this species from Dutch and British Guiana; Mr. 
Salvin collected two fine examples in the Chagres River. 
I formerly considered it possible that the fish described by Hancock might be identical 
with I. brasiliensis; but having now received examples, I have convinced myself that it 
is a distinct species. 
123. AGonosToMa Microps. (Plate LXX. fig. 1.) 
Giinth. Fish. i. p. 462. 
D. 4 i A. > L. lat. 43. L. transv. 12. 
Broad bands of villiform teeth in the jaws, on the vomer, and the palatine and 
pterygoid bones. The height of the body is contained five times in the total length, 
the length of the head four times and a half; the latter is more than the distance 
between the origins of the two dorsal fins; snout much longer than the eye. Upper 
lip thick, protruding anteriorly. The maxillary extends to, or beyond, the vertical 
from the anterior margin of the eye. The interorbital space is convex. The anterior 
dorsal commences midway between the snout and the base of the caudal fin. 
Mr. Salvin has collected specimens of this species (of which we have given a detailed 
description, /. c.) in the Rio Guacalate. 
124. AGonostoMA NasuTUM. (Plate LXX. fig. 2.) ' 
Agonostoma nasutum, Giinth. Fish. iii. p. 463. 
Dajaus' elongatus, Kner & Steindachner, Sitzgsber. bayer. Ak. Wiss. 1863, p. 222; and Abhandl. 
bayer. Ak. Wiss. 1865, p. 6, Taf. 1. fig. 2. 
nasutus, Kner & Steindachner, /. c. p. 8. 
D.4|;.. A.3  L. lat. 42. _L. transy. 12. 
Rather narrow bands of villiform teeth in the jaws, on the vomer, and palatine bones. 
The height of the body equals the length of the head, and is one-fifth of the total. 
‘ See Zool. Record, ii. p. 192. 
