DE. GUNTHBR ON THE FISHES OF CENTRAL AMERICA. 467 



is insei-ted behind the vertical from the upper end of the gill-opening. Dorsal spines 

 rather feeble, the length of the twelfth being two-sevenths of that of the head. Pectoral 

 two-thirds as long as the head. Upper parts blackish, each scale with a black base ; 

 lower parts reddish, with a broad blackish band from behind the pectoral to the base 

 of the caudal ; many scales within or below the band with a black spot in the upper 

 or lower angle ; each scale on the side of the head with a black spot ; chin and throat 

 violet. The spinous dorsal black, with yellowish margin ; the soft parts of the vertical 

 fins with blackish spots. 



This species inhabits the Lake of Amatitlan, where Mr. Salvin obtained numerous 

 examples up to 7 inches in length. 



Description. — The profile of the head and nape forms a curve. Head as high as long ; 

 snout rather elevated ; prseorbital wider than the eye, the diameter of which is a little 

 more than one-fifth of the length of the head, and about three-fifths of the width of the 

 interorbital space. Cleft of the mouth narrow, horizontal, the upper jaw slightly over- 

 lapping the lower, and the maxillary not extending backwards as far as the anterior 

 margin of the orbit. The six front teeth of the outer series are the longest, deep 

 brown. The orbit is considerably below the upper profile of the head, and somewhat 

 nearer to the end of the opevcle than to that of the snout. Opercles scaly, the scales 

 on the cheek in four or five series, and smaller than those on the opercle. Vertical fins 

 not scaly at the base ; the soft dorsal and anal do not reach far beyond the root of the 

 caudal. Free portion of tail a little higher than long. Caudal subtruncated, two- 

 ninths of the total length. Pectoral three-fourths as long as the head ; ventral with 

 the outer ray slightly produced, rather longer than the pectoral, and reaching nearly to 

 the vent. 



186. Herds ieregularis. (Plate LXXVHI. fig. 2.) 

 Theraps irregularis, Gunth. Fish. iv. p. 284. 



D. Y6- A- I^TO- L. lat. 35. L. transv. 4/14. 

 The fold of the lower lip is interrupted in the middle. The height of the body is 

 nearly equal to the length of the head, which is two-sevenths of the total (the caudal fin 

 not included). Head longer than high, with the snout compressed and prominent; the 

 length of the snout is two-fifths of that of the head, and twice or more than twice the 

 width of the orbit. The cleft of the mouth is small, extending backwards somewhat 

 behind the vertical from the nostril ; upper jaw slightly overlapping the lower ; teeth 

 in a naiTOW band, those of the outer series largest. Preeorbital wider than tlie orbit, 

 its width being equal to that of the interorbital space, which is rather convex. The eye 

 is situated immediately below the upper profile, its centre being a little behind the 

 middle of the length of the head. Scales on the cheek small, in six oblique series. 

 Scales on the opercles as lai-ge as those on the neck ; those near the base of the dorsal 

 and on the abdomen very small. Scales finely serrated. The dorr^al fin commences 



3s2 



