eigenmann: the FRESHWATER FISHES OF BRITISH GUIANA 369 



of the lateral line; a dark deep-lying line; two small deep-lying black spots at the 

 bases of the caudal lobes; no caudal spot; caudal, except the middle of the base of 

 the lobes, dusky; base and margin of anal dotted, the middle hyaline; sides of head 

 and body profusely dotted, the dots on the flanks and back margining the scales, 

 the margin consisting of a single row of chromatophores on the flank, of several 

 rows on the back; dots over the anal muscles following the intermuscular septa. 

 Cotypes all very much lighter. 



In one of the Crab Fall specimens the humeral spot is conspicuous, owing 

 to the expansion of the chromatophores. 



Holobrycon Eigenmann. 



Holobrycon Eigenmann, Ann. Carnegie Mus., VI, 1909, 33. 



Type, Brycon pesu Midler and Troschel. 



Lower jaw with two series of teeth, those of the outer series lobed, those of 

 the inner series conical. Inner series consisting of a pair of conical teeth near the 

 symphysis and a series of much smaller teeth on the posterior part of the sides of 

 lower jaw; upper jaw with three or more series of teeth. No fontanels in half- 

 grown or adult specimens. 



225. Holobrycon pesu (Muller and Troschel). (Plate LIV, fig. 1.) 



"Pesu." 

 Brycon pesu Muller and Troschel, Horse Ichth., 1, 1845, 30, pi. 7, fig. 1 ; in Schom- 



burgk, Reisen, III, 1848, 635 (Lower Essequibo and Mazaruni). — Gunther, 



Catalogue, V, 1864, 336. — Eigenmann and Eigenmann, Proc. U. S. Nat. 



Mus., XIV, 1891, 55. 

 Holobrycon pesu Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, 



431. 



I have examined the type in Berlin and: 



One specimen, 80 mm'. Warraputa Cataract. (C. M. Cat. No. 1809.) 



Two specimens, 102-116 mm. Crab Falls. (C. M. Cat. No. 1810; I. U. Cat. 

 No. 12106.) 



One specimen, 84 mm. Gluck Island. (C. M. Cat. No. 1811.) 



Seven specimens, 78-100 mm. Rockstone. (C. M. Cat. No. 1812a-6; I. U. 

 Cat. No. 12103.) 



Eighteen specimens, 29-109 mm. Bartica. (C. M. Cat, No. 1813a-rf; 

 I. U. Cat. No. 12104.) 



One specimen, 61 mm. Wismar. (C. M. Cat. No. 1814a.) 



