194 MEMOIRS OF THE CARNEGIE MUSEUM 



less than diameter of eye. Lateral shields small, of uniform height, height 2.5-3.3 

 in eye, hooks highest above tip of anal fin. Humeral process four times as long 

 as broad, spine-like. 



Sides and back covered with minute black dots, thickest at base of dorsal 

 and caudal fins, white underneath. 



63. Hemidoras carinatus (Linnaeus). 



Silurus carinatus Linnj^us, Syst. Nat., ed. 12, 1, 1766, 504.— Block and Schnei- 

 der, Syst. Ichth., 1801, 108. 



Doras carinatus Lacepede, Hist. Nat. Poiss., V, 1803, 116 (Surinam).— Cuvier 

 and Valenciennes, Hist. Nat. Poiss., XV, 1840, 288, pi. 442 (Cayenne).— 

 MtJLLER and Troschel, in Schomburgk, Reisen, HI, 1848, 629 (Essequibo).— 

 Bleeker, Ichth. Arch. Ind. Prodr., I, 1858, 54; Nederl. Tijdschr. Dierk., I, 

 1863, 13 (name only); " Silures de Suriname," 1864, 31 (Surinam). 



Doras (Oxydoras) carinatus Kner, SB. Akad. Wiss. Wien, XVII, 1855, 144 

 (Surinam) . 



Oxydoras carinatus Gijnther, Catalogue, V, 1864, 206 (Surinam; Essequibo River) .— 

 Vaillant, Bull. Soc. Philom. (7), IV, 1880, 154 (Calderon). 



Hemidoras carinatus Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., (2), I, 

 1888, 158; Occasional Papers Cal. Acad. Sci., 1, 1890, 258.— Eigenmann, Repts. 

 Princeton Univ. Exp. Patagonia, III, 1910, 394. 



Doras oxtjrhynchus Valenciennes, in Humboldt, Rec. Obs. ZooL, II, 1833, 184. 

 One hundred and thirty-three specimens, 44-320 mm. Tumatumari. (C. M. 



Cat. No. lQ31a-z; I. U. Cat. No. 12025.) 



One specimen, 95 mm. Bartica. (C. M. Cat. No. 1632.) 



Ninety-two specimens, 48-267 mm. Rockstone. (C. M. Cat. No. 1633a-i; 



I. U. Cat. No. 12026.) 



Three specimens, 45, 113, and 247 mm. Georgetown market. (C. M. Cat. 



No. 1634a; I. U. Cat. No. 12027.) 



One hundred and sixteen specimens, 39-140 mm. Crab Falls. (C. M. Cat. 



No. 1635a-i; I. U. Cat. No. 12028.) 



Head 3.16-3.33; depth 4.25-4.5; D. 1,6; A. 11-14; lateral plates 33; eye 3- 



4.5 in the head, 1.5-2.75 in the snout, the snout proportionately longer in the 



old individuals; interorbital 1.3-1.5 in the eye. 



Heavy below the dorsal, the width 1.25 in the depth; caudal peduncle as 



wide as deep, its depth less than distance of anal from the lower caudal rays; 



occipital area roof-shaped, with a median groove which is not continued to the 



