DE. GITjSTTHEE OJST THE FISHES OF CEKTRAL AMERICA. ^57 



The distance between the vent and the root of the ventral is less than one-half of the 

 length of the head. 



'a'- 



170. Herds eeythk^us. (Plate LXXV. fig. 2.) 

 D. ~. A. g. L. lat. 31. L. transv. 61/14. 



Lips thick, with broad free margin m 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 sjiine is less than one-third of that of the head. 

 The dejith 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//. 

 lahiatus. This, however, is not the case, all the specimens being males, and the speci- 

 men of //. erythrceus larger than one of the two of //. lahiatus. Besides, it appears to 

 be sufiiciently 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 ; prajorbital 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 

 ventral and the vent is one-half of the length of the head. 



171. Hekos LOBOCHiLUS. (Plate LXXV. fig. 1.) 



D. i]^. A. 8^). L. lat. 32. L. transv. 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. 3 B 



