166 MEMOIRS OF THE CARNEGIE MUSEUM 



length from eye to caudal. Upper caudal lobe more pointed than in quelen, equal 

 to the length of the head. Ashy to black, with darker mottlings, or plain, other- 

 wise as in quelen. 



One of the types, 262 mm. long, in the Jardin des Plantes has the maxillary 

 barbel extending to the second third of the adipose only (the specimen mentioned 

 by Cuvier and Valenciennes from Guayaquil is another species), upper caudal 

 lobes rounded, the fourth ray longest. 



41. Rhamdia holomelas (Gunther). 

 Pimelodus holomelas Gunther, Ann. and Mag. Nat. Hist., (3), XXII, 1863, 442 



(Essequibo); Catalogue, V, 1864, 120 (Essequibo). 



I have examined the types in the British Museum and seven specimens, 275- 

 345 mm. Lama Stop-Off . (C. M. Cat. No. 1600« and 2227a-c; I. U. Cat. No. 12413.) 



Head 4-4.2; depth 5.5-5.66; D. 6; A. 11-13; adipose dorsal 2-2.4 in the length. 



Head about an orbital diameter longer than broad, its depth half of its length; 

 interorbital flat, the snout distinctly depressed, the upper jaw longer; premax- 

 illary band of teeth five and a half times as long as deep, a distinct backward pro- 

 jecting angle laterally; maxillary barbel extending beyond the base of the pectoral 

 but not to its tip, post-mental a little beyond the base of the pectoral. Caudal cleft 

 to the base, one short ray on either side of the cleft; the second ray of the upper lobe 

 nearly as long as the third and fourth ; both lobes rounded ; pectoral spine equal to 

 the postorbital portion of the head or a little longer, with retrorse hooks in front, 

 slightly rough near the middle behind. Black, with obscure marblings. 



42. Rhamdia arekaima (Schomburgk) . 

 Pimelodus arekaima Schomburgk, Fishes Brit. Guiana, I, 1841, 178 (not pi. 5), 



(Upper Essequibo). — Muller and Troschel, in Schomburgk, Reisen, III, 



1848, 643 (all rivers of the savannah). 

 Pimelodus multiradiatus Kner, SB. Akad. Wiss. Wien, XXVI, 1857, 414 (Borba 



on the Rio Madeira; Forte do Rio Branco on the Rio Takutu). 

 Notoglanis multiradiatus Gunther, Catalogue, V, 1864, 136 (copied). 

 Rhamdia multiradiatus Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., (2), I, 



1888, 126 (name) ; Occasional Papers Cal. Acad. Sci., 1, 1890, 130. — Eigenmann, 



Repts. Princeton Univ. Exp. Patagonia, III, 1910, 386, part. 



Habitat, Amazon and its tributaries, and northward. 



This species is placed here on the authority of Schomburgk. The plate of 

 Schomburgk 's arekaima is apparently Pimelodus clarias and the description does 

 not fit it. The specimen from which the drawing was made was said to be two feet 

 three inches long, of fine flavor, and called "Tiger fish." 



