352 MEMOIRS OF THE CARNEGIE MUSEUM 



on the cheeks; base and tip of dorsal hyaline, the middle with chromatophores; 

 adipose dotted; caudal nearly uniformly dotted, a small area at base of each lobe 

 free from chromatophores; anal lobe and a streak through its middle free from pig- 

 ment; ventrals and pectorals practically free from pigment. 



212. Astyanax essequibensis Eigenmann. (Plate LI. fig. 2.) 



Astyanax essequibensis Eigenmann, Ann. Carnegie Mus., VI, 1909, 17; Repts. 



Princeton Univ. Exp. Patagonia, III, 1910, 434. 



Type, 53 mm. Tumatumari. (Carnegie Museum Catalog of Fishes No. 

 1018.) 



Cotypes, ninety-six specimens, 40-68 mm. Tumatumari. (C. M. Cat. No. 

 1019a-z; I. U. Cat, No. 11721.) 



Cotype, one specimen, 44 mm. Bartica. (C. M. Cat, No. 1020.) 



Cotypes, three specimens, 41-48 mm. Rockstone. (C. M. Cat. No. 1021a; 

 I. U. Cat. No. 11723.) 



Cotypes, seventy-five specimens, 39-57 mm. Crab Falls. (C. M. Cat, No. 

 1022a-z; I. U. Cat. No. 11723.) 



Allied to A. paucidens, but having a well-developed humeral spot. 



Head about 4; depth 3.33; D. 11; A. 20-22; scales 5-33 to 35-4; eye 2.3; 

 interorbital 3. 



Elongate, the ventral profile regularly arched; dorsal profile with an angle at 

 the origin of the dorsal, not depressed over the eye; preventral area flat, postven- 

 tral narrowly rounded; predorsal area rounded, with a median series of eight or 

 nine scales. 



Occipital process about one-fifth of the space from its base to the dorsal, bordered 

 by three scales; interorbital nearly flat, with marginal grooves; frontal fontanel 

 narrow, longer than the parietal; second suborbital leaving a triangular naked area 

 below its junction with the first; maxillary 3 in the head; premaxillary with two to 

 four teeth in the front series, which is parallel with the second series; five teeth in 

 the second row, their denticles arranged in a distinct crescent; maxillary with three 

 teeth; mandible with four graduated teeth and abruptly smaller ones on the sides. 



Scales as in A. guianensis, but fewer scales on the base of the caudal lobe. 



Dorsal and ventrals equidistant from tip of snout; highest dorsal ray about 

 3.75 in the length; origin of dorsal about equidistant from tip of snout and tip of 

 adipose; anal emarginate; ventrals not quite reaching anal; pectorals to ventrals. 



Highly iridescent, a- few chromatophores on cheek and opercles; an oblique 

 dark band crosses the second, third, and fourth scales of the lateral line, another 



