1528 Bulletin 47, United States National Mnseum. 



aaaa. Aual spines 5, rarely or never 6; dorsal rays XVI, 11 or 12. 



j. Body rather elongate, tlie depth 2f in length ; scales :!2. pavonaceus, 1945 

 jj. Body moderately deep, the depth 2| in length; hody wiih cross hands and 

 pearly dots. altifrons, 1946. 



jjj. Body deep, tlie depth 2 J in length; scaleH 30; coloration nearly plain, the 

 fins with dark spots. beani, 1947. 



aaaaa. Aual spines normally 4 (very rarely 5). Dorsal rays XV or XVI, 10 to 12; hody 

 rather deep, compressed, the depth 2.^ in length; body and fins with dark- 

 brown spots. tetracanthus, 1948. 



1924. HEKOS FRIEDUlCHSTIIALi, Heckel. 



Head 2? ; depth 24; eye 3[; in head, equal to snout. D. XVIII, 9 or 10; 

 A. VIII or IX, 9 or 7; scales 4-31-12. Fold of lower lip contiunous in 

 middle. Scales on cheek in 7 series. Aiitero-inferior margin of preorbi- 

 tal concave, the greatest width of this bone only I that of orbit. Length 

 of twelfth dorsal spine f tliat of head. Longest dorsal ray li in head; 

 longest anal ray li in heiid. Yellowish olive, with 6 or 7 blackish cross 

 bands;* a black band from eye to ujiper part of root of caudal, inter- 

 rupted by the interspaces between cross bands, the origin and end of this 

 band are edged with yellow; subopercnlum with a black ocellus; an 

 oblique black streak from eye toward ocellus. Length 5 inches. Lake 

 Peten, Lake Nicaragua, and its outlet, the Kio San Juan. 



Meros friedrichsthali, Heckel, Flussflsche Brasil, 381, 1840, Rio San Juan, Nicaragua; 

 GiJNTHEK, Cat. Fishes, iv, 294, 1862; GOnther, Fish. Centr. Am., 459, 1869. 



192.5. HEROS SALVIXI, Giinther. 



Head 2|; depth 2^. D. XVII, 10; A. VIII or IX, 7; scales 5-29-10. 

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

 eye, pointed; cleft of mouth very oblique; lower jaw j)rojecting; max- 

 illary not quite extending to vertical from anterior margin of orbit; eye 

 immediately below upper profile, in middle of length of head; suboper- 

 culum of moderate width, with 1 series of scales; preorbital a little nar- 

 rower than orbit, with the antero-inferior margin concave. Length of 

 twelfth dorsal spine f that of head in specimens from Lake Peten, and i 

 in those from Santa Isabel. Fold of lower lip continuous in middle; 

 scales of cheek in 5 series. Base of soft dorsal scaly. Distance between 

 dorsal and caudal considerably less than depth of free jiortion of tail; 

 distance between vent and root of ventrala f length of head. Dark 

 greenish olive, with a black baud, edged with yellow, running from 

 snout, through eye, to root of caudal, most distinct on head, but inter- 

 rupted (in tail by lighter interspaces; it passes a black lateral spot, and, 

 in young individuals, terminates in another black spot; an irregular 

 black band along back, below base of dorsal fin ; sometimes 3 bands across 

 upper surface of head; a blue horizontal line below orbit; a more or less 

 distinct black ocellus on sul)operculum sometimes entirely absent; fins 

 blackish, immaculate, or with faint dots only in small number; 



* These bands not evident in specimens from Nicaragua examined by us (U. S. 

 Mus., No. 39918). 



