278 THE AMERICAN CHARACIDAE. 



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

 bordered by 4 scales on the sides, of which the first is not larger than the suc- 

 ceeding one. Interorbital rounded. Frontal fontanel but half the length 

 of the parietal. Second suborbital leaving a naked strip a fourth as wide as its 

 greatest width around its entire margin. Maxillary not quite equal to the 

 eye, 3f in the head. Mandible 2| in the head. Premaxillary with four teeth 

 in an approximately straight line in the outer row, five teeth in the inner row. 

 Maxillary with a single tooth. Lower jaw with four large teeth and some 

 smaller ones on the side. 



Gill-rakers 8 4- 14. 



Scales strictly cycloid, with several inconspicuous striae, everj^where very 

 regularly imbricate, the exposed edges, at a maximum twice as high as wide; 

 no interpolated scales or rows of scales. Anal sheath inconspicuous, of a single 

 row of scales; axillary scale nearly as long as eye. Lateral line but little 

 decurved, the rows of scales below it parallel with it. 



Origin of dorsal in middle of body, its height 4 in the length. Origin of 

 anal but little behind the vertical from the last dorsal ray. Anal but slightly 

 emarginate, but its anterior rays nearly three times as long as the last; base 

 of anal not equal to the distance from the dorsal to the tip of the adipose. Ori- 

 gin of ventrals below the vertical from the second scale in front of the dorsal, 

 not quite reaching the anal. Pectorals reaching beyond origin of ventrals. 



A dark, vertical humeral spot crossing the third and fourth scales of the 

 lateral fine, followed and preceded by a light area; back dark, sides and below 

 light metallic silvery, a series of dark stripes between successive rows of scales 

 most conspicuous along the middle of the sides; a dark band along the caudal 

 peduncle, narrowed and continued on the middle rays; sides of head dotted. 



. 33. AsTYANAX WAPPi (Cuvier and Valenciennes). 

 Plate 54, fig. 4. 



Tetragonoptcrus wappi Cuvier & Valenciennes, Hist. nat. poissons, 1848, 22, p. 153 (Guiana) ; Guntheb, 

 Cat. tishes Brit, mus., 1864, 5, p 326 (British Guiana); Eigenmann & Eigenmann, Proc. U. S. 

 N. M., 1891, 14, p. 53; Ulrey, Ann. N. Y. acad. sci., 1895, 8, p. 278. 



Astyanax wappi Eigenmann, Kept. Princeton univ. exped. Patagonia, 1910, 3, p. 433; Mem. Carnegie 

 mus., 1912, 5, p. 355, pi. 52, fig. l.i 



Habitat. — British Guiana. 



I have examined the type (2336 Museum hist. nat. Paris) total length 105 

 mm. and the specimen in the British Museum. 



Head 3.66; depth 3; scales 7-38-6; eye 1.5 in the very convex interorbital, 



' The figure is taken from the specimen in the British Museum. 



