7. HERosi. 289 



tip. Eye as distant from the extremity of the snout as from that of 

 the operculum. Scales on the cheek considerably smaller than those 

 on the opercles. 



Vertical fins scaleless. Dorsal spines of moderate strength and 

 length, the length of the twelfth being one-third of that of the head ; 

 the soft dorsal and anal extend somewhat beyond the root of the 

 caudal. The free portion of the tail is nearly as long as high. Anal 

 spines strong and long. Caudal rounded, one-fifth of the total length. 

 Pectoral shorter than tbt' head, extending nearly to the origin of the 

 anal fin. The distance of the vent from the root of the ventral is 

 three-quarters of the Icigth of the head. 



Orange-coloured or purplish-brown, with a more or less irregular 

 deep-black band along the middle of the tail ; sometimes a series of 

 more or less confluent black blotches on the back. Mature specimens 

 have the whole of the lower parts of the head, belly and tail deep 

 black. Dorsal, caudal and pectoral orange-coloured or purplish-brown, 

 with a few scattered spots posteriorly ; anal and ventral black. 



Young specimens have no black, except the band on the tail ; their 

 dorsal spines are proportionally longer, the length of the twelfth being 

 contained twice and a fourth in that of the head. 



6. Heros spilurus. 

 D.l^. A.g. L. lat. 29. L. transv. fj. 



The fold of the lower lip is interrupted in the middle ; four scries 

 of scales on the cheek. No spot on the temple ; a large black spot 

 on the middle of the root of the cavidal. 



Guatemala. 

 a-h. From Mr. 0. Salvin's Collection. 



Description. — The height of the body is one-half of the total length 

 (without caudal), the length of the head nearly one-third. Head a 

 little higher than long ; snout of moderate extent, its length being 

 two-fifths of that of the head. The diameter of the eye is two- 

 sevenths of the length of the head, two-thirds of that of the snout, 

 and less than the width of the interorbital space, which is convex ; 

 the eye is situated below the upper profile, a little nearer to the ex- 

 tremity of the operculum than to that of the snout. Pracorbital as 

 wide as the orbit. Cleft of the mouth very narrow, scarcely oblique, 

 with the jaws equal anteriorly. Opercles scaly. 



Vertical fins scaly at the base. Dorsal spines of modem te length 

 and strength, the length of the twelfth being contained twice and a 

 third in that of the head. The points of the soft dorsal and anal 

 extend to the middle of the caudal. Caudal rounded. The distance 

 between dorsal and caudal is less than the depth of the tail. Pec- 

 toral nearly as long as the head, extending to the fourth anal spine ; 

 the outer ventral ray prolonged into a short filament. 



Greenish-olive, with nine dark vertical bands ; a large, i-ouiidish 

 black spot on the middle of the root of the caudal. Ciiudal and the 

 posterior part of the dorsal and anal with whitish spots. 



Length of the largest specimen 3| inches. 



VOL. IV. u 



