326 MEMOIRS OP THE CARNEGIE MUSEUM. 



46. Pygidium gracilior Eigenmann. (Plate L, fig. 3.) 

 Pygidium gracilior Eigenmann, Mem. Carnegie Mus., V, 1912, p. 213 (Erukin). 



Habitat. — Lower Potaro River, British Guiana. 

 1730, C. M., 27 mm., type. Erukin. Eigenmann. 



Head 6; depth 9; D. 8; A. 6; eye about 2 in the snout; interorbital a little 

 greater than snout, snout 3 in the head. 



Slender, head as broad as long; maxillary barbel reaching tip of pectoral; nasal 

 barbel to origin of pectoral; outer pectoral ray prolonged, about equal to the head 

 in length. Origin of the anal under origin of dorsal; distance from origin of dorsal 

 to origin of caudal 3.5 in the length; length of caudal 5 in the length. 



All upper parts obscurely spotted. 



47. Pygidium amazonicum (Steindachner). (Plate XLVI, figs. 3, 4.) 

 Tricho?nycterus arnazonicus Steindachner, Flussf. Sudani., IV, 1882, p. 29, pi. VI, 



figs. 4-4a (Cudajas). 

 Pygidium amazonicum Eigenmann & Eigenmann, Proc. Gal. Acad. Sci. (2), II, 



1889, p. 53; Occasional Papers Cal. Acad. Sci., I, 1890, p. 338; Proc. U. S. Nat. 



Mus., XIV, 1891, p. 37; Eigenmann, Reports Princeton Univ. Exped. Pata- 

 gonia, III, 1910, p. 400. 



Habitat. — Amazon, at Cudajas. 



This species is known from the type, a specimen 60 mm. long. 



Head a little over 6, equal to the depth; D. 8; A. 7; P. 6; eye entirely in front 

 of the middle of the head; interorbital a little greater than the eye; width of head 

 nearly equal to its length. 



Head greatly depressed, caudal peduncle strongly compressed; nasal barbels 

 reaching nearly to gill-opening; maxillary barbel to the end of the first third of the 

 upper pectoral ray, lower barbel to the base of the pectoral; dorsal and anal opposite 

 each other; ventrals very short, 2 in the head; caudal rounded; upper pectoral ray 

 nearly equal to the head. 



Chocolate brown, with faint darker spots on the caudal peduncle; rays of dorsal 

 and caudal dotted with violet. 



48. Pygidium hasemani Eigenmann. (Plate L, fig. 4.) 

 Pygidium hasemani Eigenmann, Ind. Univ. Studies, No. 20, March, 1914, p. 48. 

 5238 and 5239, C. M., type and paratypes, many, largest under 18 mm. Santarem. 



Haseman. 



Habitat. — Amazon at Santarem to Bolivia. 

 76023, C. M., about 16 mm. San Joaquin. Sept. 4, 1909. Haseman. 



