DR. GUNTHER ON THE FISHES OF CENTRAL AMERICA. 455 
wards across the nape; the second, third, and fourth below the dorsal spines; the 
seventh across the free portion of the tail. A large, black, white-edged ocellus on the 
root of the caudal. Fins blackish; pectoral yellowish towards the base. 
Mr. Salvin obtained three examples, 7 inches long, at Lake Peten. 
167. Heros aureus. (Plate LX XIII. fig. 2. 
Giinth. Fish. iv, p. 292. 
D. = AM. 2 L. lat. 33. L. transv. 6/13. 
The fold of the lower lip is continuous in the middle. Scales on the cheek in tive 
series. Base of the dorsal scaleless. The height of the body is contained twice and a 
third in the total length (without caudal), the length of the head three times. Head 
as high as long; snout somewhat elevated, with the cleft of the mouth oblique and 
with the jaws equal anteriorly ; prorbital as wide as the orbit. The eye is a little 
nearer to the extremity of the operculum than to that of the snout. Dorsal spines 
rather slender, the length of the twelfth being a little less than one-half of that of the 
head. ‘The distance between the dorsal and caudal is somewhat less than the greatest 
depth of the free portion of the tail. Caudal slightly emarginate. The distance 
between the vent and the root of the ventral is one-third of the length of the head. 
Yellowish-olive, with six dark cross bands, extending downwards to a yellow longi- 
tudinal band running from above the pectoral to the lower half of the base of the 
caudal. The third cross band terminates in a large black lateral spot ; sides of the 
head with several bluish dots, and with a blackish spot on the operculum and suboper- 
culum, darkest on the latter bone. Fins light-coloured, immaculate. 
Two specimens, 4 and 5 inches long, were collected by Messrs. Salvin and Godman 
at Yzabal and in the Rio Motagua. 
168. Heros arrinis. (Plate LXXIX. fig. 1.) 
Ginth. Fish. iv. p. 292. 
D. gy Avge LL. lat. 29. L. transv. 5/12. 
The fold of the lower lip is continuous m the middle. Scales on the cheek in four 
series. The height of the body is contained twice and two-fifths in the total length 
(without caudal), the length of the head twice and three-fourths. Head as high as 
long; snout compressed, elevated, with the cleft of the mouth oblique and with the 
lower jaw prominent. Preorbital wider than the orbit (in the larger individuals) ; the 
eye is considerably nearer to the extremity of the operculum than to that of the snout. 
Dorsal and anal fins entirely scaleless; dorsal spines rather strong and long, the length 
of the twelfth being two-fifths of that of the head. Anal spines very strong. ‘The free 
portion of the tail is a little higher than long. Caudal slightly emarginate, two-ninths 
of the total length. The distance between the vent and the root of the ventral is one- 
