eigenmann: the FRESHWATER FISHES OF BRITISH GUIANA 389 



Metynnis Cope. 



Metynnis Cope, Proc. Am. Philos. Soc, XVII, 1878, 692 iluna). 



Sedkina Fowler, Proc. Acad. Nat. Sci. Phila., 1906, 478 (lippincottianus). 



Type, Metynnis luna Cope. 



Belly trenchant, serrate; premaxillary with two series of teeth; mandible with 

 a pair of teeth behind the front series; a procumbent predorsal spine; adipose fin 

 more than half the length of the dorsal; free margin of anal slightly convex or with 

 a lobe in front or sinuate; dorsal falcate. 



Key to the Guiana Species of Metynnis. 



a. Gill-rakers 14 + 18-20, about one-fourth the length- of the eye; adipose twice as long as its distance from 

 the dorsal, or longer; caudal lunate; anal low, its margin sinuate, the rays at the beginning of the last 

 third about half as long as eye. A. 40-43; D. 19-20; abdominal serrse 27-33; depth 1.1-1.24. Sides 



with obscure cross-bands, a humeral spot hypsauchen. 



aa. Gill-rakers 7-12 + 11-13, about one-sixth to one-fourth the length of the eye; adipose but little longer than 

 its distance from the dorsal. Caudal very slightly emarginate; anal high, rays of the beginning 

 of the last third equal to eye. A. 37-40; D. 17-21; seme 31-35; depth 1.22-1.3; head 3.66; dorsal 

 in the larger spotted; dorsal, adipose, caudal, and anal margined with dusky. A dark oblique bar 

 extending from near end of pectoral up toward origin of dorsal, broken into two spots frequently, 

 sides obscurely spotted maculatus. 



245. Metynnis hypsauchen (Muller and Troschel). 



Myletes hypsauchen Muller and Troschel, Horse Ichth., I, 1845, 38, pi. 10, fig. 

 1 (Essequibo; Guiana). — Ctjvier and Valenciennes, Hist. Nat. Poiss., XXII, 

 1848, 219 (Amazon). — Muller and Troschel, in Schomburgk, Reisen, III, 

 1848, 637 (Tapacuma Lake). — Kner, "Familie der Characinen," ii, 1859, 18 

 (Caigara; Marabitanos) . — Gunther, Catalogue, V, 1864, 376 (Essequibo 

 River). — Steindachner, "Flussfische Stidamerika's," ii, 1881, 28 (Santarem; 

 Teffe; Rio Trombetas; Rio Guapore); iv, 1882, 16 (Huallaga). — Eigenmann 

 and Eigenmann, Proc. U. S. Nat. Mus., XIV, 1891, 61. — ? Boulenger, 

 Trans. Zool. Soc. London, XIV, 1896, 37 (Descalvados) ; ? Boll. Mus. Zool. 

 ed Anat. Comp. Torino, XV, 1900, — (near Corumba). — Eigenmann and 

 Ogle, Proc. U. S. Nat. Mus., XXXIII, 1907, 35 (South America).— Eigen- 

 mann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, 443. 

 I have examined the types and: 

 Eleven specimens, 60-110 mm. Rockstone. (C. M. Cat. No. 1125a-d; I. U. 



Cat. No. 11641.) 



Four specimens, 61-70 mm. Twoca Pan. (C. M. Cat. No. 1124a; I. U. Cat. 



No. 11642). 



