340 MEMOIRS OF THE CARNEGIE MUSEUM 



caudal. Dorsal with a round, intensely black spot on the first seven rays, the tips 

 of the second and third rays white. The distal half of the longest anal ray and the 

 tip of the next ray are also white. All the fin-rays dusky. In life, with a general 

 rosy tinge, especially above the anal, and the base of caudal lobes and ventrals. 

 Anal lobe and base and tip of dorsal lobe bright orange. 



199. Hyphessobrycon riddlei Meek. 

 Hemigrammus riddlei Meek, MS., in Eigenmann and Ogle, Proc. U. 8. Nat. 



Mus., XXXIII, 1907, 13 (Los Castillos). 

 Hyphessobrycon riddlei Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 



1910, 436. 



One specimen, 23 mm. Rockstone. (C. M. Cat. No. 1248.) 



Depth 3.8; D. 11; A. 20; scales 4-31-3; eye 3 in the head. 



Frontal fontanel triangular, very small, narrower than the parietal, and half 

 the length of the latter without the occipital groove. Second suborbital in con- 

 tact with the preopercle. Mouth small; maxillary very little shorter than the 

 eye, about 3 in the head, with six conical teeth; premaxillary with twelve small 

 teeth in the inner row and two in the outer. 



Lateral line with pores on the anterior half of the scales. 



Origin of the dorsal equidistant between the snout and the caudal. Origin 

 of the anal on the vertical from the first scale behind the dorsal; anal slightly falcate. 



A small dark spot at the base of each caudal lobe, and a row of small black spots 

 along the base of the anal; no humeral spot; no fin markings. 



200. Hyphessobrycon gracilis (Reinhardt). (Plate XLIX, fig. 4.) 

 Tetragonopterus gracilis Reinhardt, in Liitken, Overs. Dan. Vidensk. Selsk. 



For., 1874, 133 (Lagoa Santo). — Lutken, Vidensk. Selsk. Skr., (5), XII, 



1875, 217, pi. 5, fig. 16 (Rio das Velhas). — Eigenmann and Eigenmann, Proc. 



U. S. Nat, Mus., XIV, 1891, 53.— Ulrey, Ann. N. Y. Acad. Sci., VIII, 1895, 



286. — Boulenger, Boll. Mus. Zool. ed. Anat. Comp. Torino, X, 1895, 3 (Villa 



Rica). 

 Hemigrammus gracilis Eigenmann and Ogle, Proc. U. S. Nat. Mus., XXXVIII, 



1907, 15 (Lagoa Santa). 

 Hyphessobrycon gracilis Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 



1910, 436. 

 Tetragonopterus schmardm Ulrey (not of Steindachner), Ann. N. Y. Acad. Sci., 



VIII, 1895, 286 (Para). 



