EIGENMANN: THE PYGIDIID^E, A FAMILY OF SOUTH AMERICAN CATFISHES. 295 



long as high; maxillary barbel reaching pectoral; origin of anal under end of dorsal; 

 distance of origin of dorsal from caudal two and one-half to three in its dis- 

 tance from the snout; pectoral ray not prolonged; origin of ventrals equidistant 

 from tips of snout and caudal; caudal truncate; sides and back with large dark 

 spots. 



8. Pygidium eichorniarum (Ribeiro). (Plate XLIV, fig. 3). 

 Trichomycterus eichorniarum Ribeiro, Comm. Linhas Telegraphicas Estrategicas 



Matto-Grosso ao Amazonas, Annexo, 5, 1912, p. 27 (Caceres). 



Habitat. — Upper Paraguay. 



Evidently allied to P. riojanum, proops, and metm. 



Known from the types, two specimens, the larger 44 mm., and 

 7556o-c, C. M., 24-30 mm. Caceres, May 27, 1909. Haseman. 

 7557a & b, C. M., 33-43 mm. Caceres, May 23, 1909. Haseman. 

 7558a, C. M., 42 mm. San Francisco, Rio Jaurii, Paraguay basin, June 10, 1909. 



Haseman. 

 7559a, C. M., 32 mm. Bastos, Rio Alegre, eight miles south of Villa de Matto- 

 Grosso, June 26, 1909. Haseman. 

 7560a-c, C. M., 39-41 mm. San Antonio, Rio Guapore, plantation of Maciel, 



July 31-Aug. 11, 1909. Haseman. 



Head 5-5.75; D. 9-10; A. 8; P. 6; posterior margin of eye slightly in advance 

 of the middle of the head; eye about 1.5-2 in the snout, 5.5-6.5 in the head, about 

 equal to the interorbital; maxillary barbel reaching to axil or middle of pectoral; 

 nasal barbel to the tip of the opercular spines or the axil of the pectoral; teeth 

 conical, a very narrow band of but two or three irregular series; origin of ventrals 

 equidistant from tip of snout and tip of caudal; origin of anal under, or but slightly 

 behind, the first dorsal ray; distance from base of last anal ray to base of caudal 

 about six times in the length; distance from origin of dorsal to base of caudal two 

 and three-quarters in its distance from the snout; caudal rounded, accessory rays 

 moderate; first pectoral ray much prolonged, with its filament nearly equal to the 

 length of the head. 



General color of P. brasiliense, back and sides profusely spotted; caudal rays 

 with numerous spots, dorsal and anal less profusely spotted. 



9. Pygidium riojanum Berg. 

 Pygidium riojanum Berg, Ann. Mus. Nac. Buenos Aires, V, 1897, p. 269; Eigen- 

 mann, Reports Princeton Univ. Exped. Patagonia, III, 1910, p. 399. 

 Habitat. — Arroyo in the Cordillera de la Rioja, northern Argentina. 



