eigenmann: the FRESHWATER FISHES OF BRITISH GUIANA 199 



Trachycorystes galeatus Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., (2), I, 



1888, 155 (Pernambuco; San Goncallo; Rio San Francisco, below the falls; 



Tabatinga; Teffe; Rio Puty); Occasional Papers Cal. Acad. Sci., I, 1890, 



279. — Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, 396. 

 Auchenipterus maculosus Cuvier and Valenciennes, Hist. Nat. Poiss., XV, 1840, 



216 (Cayenne). — Muller and Troschel, in Schomburgk, Reisen, III, 1848, 



639 (Essequibo).— Kner, SB. Akad. Wiss. Wien, XXVI, 1857, 425 (Mara- 



bitanos). — Gunther, Catalogue, V, 1864, 196 (Surinam; Essequibo). — Vail- 



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

 Auchenipterus immaculatus Cuvier and Valenciennes, Hist. Nat. Poiss., XV, 



1840, 218 (Cayenne). 

 Auchenipterus punctatus Cuvier and Valenciennes, Hist. Nat. Poiss., XV, 1840, 



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



629 (Essequibo).— Kner, SB. Akad. Wiss. Wien, XXVI, 1857, 425 (Rio 



Branco) . 

 Auchenipterus lacustris Lutken, Dan. Vidensk.-Selsk. Skr., XII, 1875, 148, with 



fig. (Rio das Velhas). 

 Auchenipterus robustus Gunther, Catalogue, V, 1864, 197 (Demerara). 

 Trachycorystes robustus Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., (2), 



I, 1888, 156 (name only). 



One specimen, 110 mm. Mud-flats, Demerara River, below Wismar. (C. M. 

 Cat. No. 1717a.) 



One specimen, 132 mm. Barima River. (C. M. Cat. No. 1718a.) 



Five specimens, 116-160 mm. Aruka River. (C. M. Cat. No. 1719a; I. U. 

 Cat. No. 12096a-6.) 



Eleven specimens, 99-195 mm. Lama Stop-Off. (C. M. Cat. No. 1720a-6; 

 I. U. Cat. No. 12093.) 



Four specimens, 130-228 mm. Georgetown trenches. (C. M. Cat. No. 1721a ; 

 I. U. Cat. No. 12094.) 



One specimen, 167 mm. Maduni Creek. (C. M. Cat. No. 2229.) 



Four specimens, 91-140 mm. Chipoo Creek. (C. M. Cat. No. 1722a-o; 

 I. U. Cat. No. 12095.) 



Head 4-4.5; depth 3.5-4; D. 1,6; A. 22-27, most frequently 24; V. 6; P. 1,6. 

 Eye 1.5-2 in snout, 5.5-6 in head, 3.5-4 in interorbital. 



Head heavy, its width equal to its length, depressed, profile but little concave 

 at the nape, rounded forward, the lower jaw entering the profile; upper surface 

 of head finely granular in the old, covered with thin smooth skin in the young; 



