460 DE. GtJNTHER ON THE FISHES OF CENTEAL AJMEEICA. 



being only two-thmls of that of the orbit. The length of the twelfth dorsal spine is 

 two-sevenths of that of the head. Yellowish-olive, with six or seven blackish cross 

 bands ; a black band from the eye to the upper part of the root of the caudal, inter- 

 rupted by the interspaces between the cross bands ; the origin and end of this band are 

 edged with yellow ; suboperculum with a black ocellus ; an oblique black streak from 

 the eye towards the ocellus. 



Lake Peten. Several examples, 5 inches long, were collected by Mr. Salvin. 



175. Herds salvini. (Plate LXXIII. fig. 3.) 



Heros salvini, Giinth. FisL. iv. p. 294. 



triagramma, Steiudaclmer, Denkschr. Akad. Wiss. Wien, xxiii. p. 70, tab. 3. fig. 2. 



D. }-J. A. ^. L. lat. 29. L. transv. 5/10. 



Fold of the lower lip continuous in the middle ; scales of the cheek in five series. 

 Prseorbital a little narrower than the orbit, with the antero-inferior margin concave. 

 Base of the soft dorsal scaly. The height of the body is contamed twice and a fourth 

 in the total length (without caudal), and the length of the head twice and three-foui'ths. 

 Head somewhat longer than high ; snout of moderate extent, longer than the eye, 

 pointed, with the cleft of the mouth very oblique, and with the lower jaw projecting ; 

 the maxillary does not quite extend to the vertical from the anterior margin of the 

 orbit. The eye is situated immediately below the upper profile, in the middle of the 

 length of the head. Suboperculum of moderate width, with one series of scales. The 

 length of the twelfth dorsal spine is two-fifths of that of the head in specimens from 

 Lake Peten, and one-third in those from Santa Isabel. The distance between dorsal and 

 caudal is considerably less than the depth of the free portion of the tail. The distance 

 between the vent and the root of the ventrals is two-fifths of the length of the head. 

 Dark greenish olive, with a black band, edged with yellow, runnmg from the snout, 

 through the eye, to the root of the caudal ; it is most distinct on the head, but inter- 

 rupted on the tail by lighter interspaces ; it passes a black lateral spot, and, in young 

 specimens, terminates in another black spot. An irregular black band along the back, 

 below the base of the dorsal fin. vSometimes three bands across the upper surface of 

 the head. A blue horizontal line below the orbit ; a more or less distinct black 

 ocellus on the suboperculum is sometimes entirely absent. Fins blackish, immacu- 

 late, or with faint dots only in small number. The sides below the black band are 

 sanguineous in mature specimens. 



The largest specimen is 4^ inches long. 



This species occurs in Lake Peten as well as in the Rio Santa Isabel ; specimens from 

 the former locality are distinguished by somewhat longer dorsal spines. H. triagramma 

 appears to have been founded on a Lake-Peten example. 



