456 DR. GUNTHER ON THE FISHES OF CENTRAL AMERICA. 
third of the length of the head. Olive, with five or six dark cross bands, the middle one 
of which has a deep-black spot where it passes the lateral lme; a more or less distinct 
black spot on the suboperculum ; sides of the head and vertical fins with bluish dark- 
edged ocelli. 
This species is very closely allied to H. awreus, but may be distinguished from it by 
larger scales, by a more backward position of the eyes, by stronger spines, &c. 
Four examples, from 3} to 5} inches long, were obtained by Mr. Salvin at Lake Peten, 
169. Heros LABIATUS. 
Giinth. Proc. Zool. Soc. 1864, p. 27, pl. 4. fig. 1. 
D. 2. Al. L. lat! 32.~ L.transv,. 6/18. 
The anterior portions of the upper and lower lips are much enlarged, each forming 
a moyeable subtriangular flap (probably in old males only). The height of the body is 
somewhat more than the length of the head, and two-fifths of the total (without caudal) ; 
the eye occupies the middle of the length of the head. Scales on the cheek in four 
series. Base of the dorsal fin almost scaleless. The length of the eighth dorsal spine is 
less than one-third of that of the head. The depth of the free portion of the tail is 
scarcely more than its length. Uniform red, or red irregularly marbled with black, or 
nearly entirely black. 
Two specimens, 63 and 7 inches long, were collected by Capt. Dow in the Lake of 
Managua; three others were lately sent by the same gentleman from the Lake of 
Nicaragua. We do not yet know the female sex and the young state of this species. 
Description. —Head rather longer than high; snout somewhat elevated; cleft of the 
mouth slightly oblique, with the lower jaw a little prominent. ‘Teeth in narrow bands, 
those of the outer series enlarged, with brown tips. The maxillary does not nearly 
attain the vertical from the front of the eye. Preorbital as wide as the orbit, the 
diameter of which is less than the extent of the snout, and one-fourth of the length of 
the head. Interorbital space somewhat convex, wider than the orbit. The eye is 
situated not quite immediately beneath the upper profile of the head, and midway 
between the end of the snout and that of the operculum. Opercles scaly, the scales 
being larger than those on the cheek; suboperculum with two series of scales. Soft 
portions of dorsal and anal fins with minute scales between the rays at their base. 
Dorsal spines of moderate length and strength, the length of the eighth dorsal spine 
being less than one-third of the length of the head. Points of the produced middle 
rays of the soft dorsal and anal reaching to the middle of the caudal fin. Caudal 
rounded, its length being contained rather more than five times in the total. Anal 
spines of nearly the same length and strength as those of the dorsal fin. Pectoral 
rounded, reaching to the fourth or fifth spine of the anal; ventral filament produced. 
