452 DR. GUNTHER ON THE FISHES OF CENTRAL AMERICA. 
length of the head nearly one-third. Head a little higher than long; snout of 
moderate extent, its length being two-fifths of that of the head. The diameter of the 
eye is two-sevenths of the length of the head, two-thirds of that of the snout, and less 
than the width of the interorbital space, which is convex; the eye is situated below 
the upper profile, a little nearer to the extremity of the operculum than to that of the 
snout. Prieorbital as wide as the orbit. Dorsal spines of moderate length and strength, 
the length of the twelfth being contained twice and a third in that of the head. ‘The 
distance between dorsal and caudal is less than the depth of the tail. Greenish olive, 
with nine dark vertical bands; a large, roundish black spot on the middle of the root 
of the caudal; no spot on the temple; caudal. and the posterior part of the dorsal and 
anal with whitish spots. 
Three examples were collected by Messrs. Salvin and Godman at Yzabal and in the 
Rio Motagua. Length 33 inches. 
163. Heros niGrorasciatus. (Plate LX XIV. fig. 3.) 
p= ALL. lat. 29. “1. ‘transy. 4/14. 
‘The lower lip is interrupted in the middle. Scales on the cheek in four or five series. 
Dark blackish brown, with nine deep-black cross bands. 
Numerous examples, from 2 to 34 inches long, were collected by Mr. Salvin in the 
Lakes of Amatitlan and Atitlan. 
Description—The height of the body is contained twice and one-sixth in the total 
length (without caudal), the length of the head thrice; the free portion of the tail is 
considerably deeper than long. Head as high as long, with the upper profile convex 
to the snout, where it is straight. Snout of moderate extent, the width of the pre- 
orbital being equal to that of the orbit. The eye is somewhat nearer to the end of the 
snout than to that of the operculum ; its diameter is considerably less than the width 
of the interorbital space, and one-fourth of the length of the head. Jaws equal in 
length. The soft dorsal and anal fins have scarcely any scales on their base, and are 
more or less produced in the middle, the longest rays reaching to the middle of the 
caudal. ‘The dorsal fin commences in the vertical from the humerus; its spines are of 
moderate strength, rather short, the length of the twelfth being somewhat less than 
one-third of that of the head. Anal spines as long as, but rather stronger than those 
of the dorsal fin. Caudal rounded, two-ninths of the total length. Pectoral as long 
as the head, without snout, extending to the second or third anal spine. Ventral but 
slightly produced. 
This spécies is very dark-coloured. The ground-colour is a dark blackish purplish 
brown. An arched black band runs ‘fromthe nape of the neck round the opercular 
margin to the interoperculum. A second is nearly concentric with the first, running 
from the nape to behind the pectoral and ventral. ‘The third is short, like a spot, 
