DR. GUNTHER ON THE FISHES OF CENTRAL AMERICA. 457 
The distance between the vent and the root of the ventral is less than one-half of the 
length of the head. 
170. Heros ErytHRaus. (Plate LXXV. fig. 2.) 
D7 AZ L lat. 81. L, transv. 64/14. 
Lips thick, with broad free margin in their entire circumference. The height of the 
body is contained twice and a third in the total length (without caudal), the length of 
the head twice and two-thirds; the eyes occupy the middle of the length of the head. 
Scales on the cheek in four or five series. Base of the soft dorsal fin with very small 
scales. 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 conspicuously more than its length. Of a 
deep orange-colour; many of the scales of the tail with a blackish spot on the base. 
- One specimen, 7 inches long, was collected by Capt. Dow in the Lake of Managua. 
I was for some time inclined to regard this fish as a variety of sex or age of H. 
labiatus. This, however, is not the case, all the specimens being males, and the speci- 
men of H. erythreus larger than one of the two of H. labiatus. Besides, it appears to 
be sufficiently distinguished by its much shorter and deeper tail. 
. Description —Head as high as long ; snout rather elevated, with the cleft of the mouth 
slightly oblique, and the lower jaw scarcely prominent. ‘Teeth in narrow bands, those 
of the outer series enlarged, with brown tips. The maxillary does not reach the 
vertical from the front margin of the eye; preorbital wider than the orbit. The 
diameter of the eye is contained nearly five times in the length of the head. Inter- 
orbital space slightly convex, much wider than the orbit. Eye situated near the upper 
profile of the head, and equidistant from the end of the snout and that of the oper- 
culum. Opercles scaly, the scales being larger than those on the cheek ; suboperculum 
with two series of scales. The soft dorsal and anal fins with a few minute scales 
running up between the bases of the rays; dorsal spines of moderate strength. Soft 
dorsal and anal slightly produced, not reaching to the middle of the caudal. Caudal 
rounded, one-fifth of the total length. Anal spines stronger but not longer than those 
of the dorsal fin. Pectoral rounded, extending to the fourth anal spine, somewhat 
shorter than the head, The outer ventral ray produced; the distance between the 
yentral and the vent is one-half of the length of the head. 
171, Heros Losocuitus. (Plate LXXYV. fig. 1.) 
D. — A, ay: L. lat. 32. L. transy, 6/14. 
Old males with the anterior portions of the upper and lower lips much enlarged, 
each forming a moveable subtriangular flap; in young males the lips are simple, the 
fold of the lower being continuous. The height of the body is contained twice and a 
third in the total length (without caudal), the length of the head twice and three- 
VOL. VI.—PART VII. aR 
