64 THE AMERICAN CHARACIDAE. 



teeth, second suborbital leaving a narrow naked area on the cheek. This genus 

 differs from Moenkhausia in having crenate instead of entire scales. 

 Habitat. — Middle and Upper Amazon. 



1. Entomolepis steindachneri (Eigenmann). 

 Plate 3, fig. 1-3, Plate 6, fig. 3. 



Tetragonoplerus lineatus Steindachner (non Perugia), Ichthyol. beitr. 1891, 15, p. 26, pi. 2, fig. 1 (Iqui- 



tos). 

 Tetragonoplerus steindachneri Eigenmann, Proc. U. S. N. M., 1893, 16, p. 53. 



Moenkhausia steindachneri Eigenmann, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 437 

 fAslyanax oligolepis Fowler (non Gtinther), Proc. Acad. nat. sci. Phil., 1906, p. 439, fig. 37 (Peruvian 



Amazon). 



Habitat. — Middle and Upper Amazon. 



Aside from the types in Vienna I have examined the following, from which 

 the present description is drawn: 



Two specimens, 20967, 71 and 74 mm. to base of caudal. Cudajas. Thayer 

 & Bourget. 



Head 3.6; depth 2.26; D. 10 or 11; A. 25 to 26; scales 5-32 to 33-4 or 4.5. 

 Eye 3-3.2; interorbital 2.4 in head. 



Deep oval, without distinct humps or depressions; pre ventral area somewhat 

 compressed, keeled; postventral area more narrowly compressed; predorsal 

 area with a blunt median keel; a median series of nine scales reaching from 

 dorsal to occipital process. 



Occipital process about one fifth of the distance of its base from the dorsal, 

 bordered by one or two scales, the first of which is unusually large; skull heavy 

 and broad; frontal fontanel nearly circular, not half as long as the occipital 

 fontanel; interorbital convex; second suborbital corrugate, leaving but a very 

 narrow naked border; interopercle distinctly visible from the side; maxillary 

 3.33 in head; four teeth in the outer series of the premaxillary, the middle two 

 close together, the third withdrawn from the line of the others; five teeth in 

 the inner series; one or two teeth on the maxillary; mandible with four large 

 graduated teeth. Gill-rakers 8 and 10, very slender, the longest two thirds of 

 the pupil. 



Scales large, crenate, very regularly imbricate, the exposed margin of those 

 on the caudal peduncle three fourths as high as the highest on the middle of the 

 sides; the scale at the base of the occipital crest much larger than usual; each 



