340 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. X. 



Color in life of a large example: Back bluish black, pale brownish 

 below; sides with 4 indistinct cross-bars, a dark blotch on sides below 

 last half of spinous portion of dorsal; cheeks with 2 distinct blue-green 

 lines and numerous spots of the same color; these spots are also present 

 on sides and breast; base of caudal with a large black spot. Dorsal fin 

 bluish black, the soft rays with a tinge of deep red and with a yellow 

 margin; caudal fin reddish blue with darker spots; anal fin dark blue, 

 the last rays reddish at tips; ventral fins slate; pectorals greenish. The 

 dark cross-bars on sides more numerous and more distinct in young. 

 Cheeks, sides and chest without blue-green lines or spots; fins all paler 

 and without red. 



Considerable variation in color is evident among our specimens. 

 Individuals taken in muddy streams are much duller, and do not possess 

 any blue-green lines and spots. 



Of this species there are numerous specimens in the present col- 

 lection, ranging in length from 2 5 to 1 5 7 mm. One of the most abundant 

 species in the streams of Panama, occurring on both slopes, from tide 

 water to the highest mountain streams. 



Habitat: Both slopes of Panama and south to Colombia, and 

 Ecuador. 



46. Genus Geophagus Heckel. 



Geophagus Heckel, Ann. Wiener Mus., II, 1840, 383 (type Geophagus 



altifrons Heckel = Sparus surinamensis Bloch). 



Satanoperca Gunther, Cat. Fish. Brit. Mus., IV, 1862, 312 (type Geopha- 

 gus acuticeps Heckel). 



Body oblong, compressed; mouth moderate; jaws with conical 

 teeth; premaxillary moderately protractile; outer gill-arch with a com- 

 pressed lamelliform lobe above, gill-rakers at or near its margin; margin 

 of lower lip not free at its middle; caudal fin emarginate to slightly 

 forked; anal spines 3. 



One species of this genus is known to occur in Panama, its range not 

 extending northward far beyond the Canal Zone. 



73. Geophagus crassilabris Steindachner. 



Geophagus (Satanoperca} crassilabris Steindachner, Sitzb. K. Ak. 



Wiss. Wien, LXXIV, 1876, 65, PI. VII (Vicinity of Candelaria, 



Isthmus of Panama). 

 Satanoperca crassilabris Jordan & Evermann, Bull. U. S. Nat. Mus., 



XLVII, 1898, 1542. 

 Geophagus crassilabris Pellegrin, fitude Pois. Fam. Cichlides, Lille, 1904, 



160 (Isthmus of Panama) ; Regan, Biol. Cent. Amer., Pisces, 1906, 16. 



