X. DESCRIPTION OF A NEW SPECIES OF PYCxIDIUM. 



By Carl H. Eigenmann. 



Pygidium barbouri. (Plate XXXII.) 

 Type: 37 mm., No. 29313, Museum Comparative Zoology. 

 Cotypes: 32 specimens from 29 to 40 mm. long. M.C.Z., No. 29314. 

 Cotypes: 2 specimens, C. M. Cat. No. 2465a-b & I. U. Cat. No. 12566. 



All specimens from the upper reaches of the Beni River, tropical 

 eastern Bolivia. 



Head 4.66; depth 7; D. 8; A. 6; eye 3 in snout, 7 in head, 2.5 in 

 space between the ejes. 



Width of head equals its length behind the posterior nares, the 

 body tapering to the caudal; nasal barbels reaching to posterior margin 

 of the eye, the longer maxillary barbel scarcely to the gill-opening 

 when laid straight back. Teeth minute, in bands. 



First pectoral ray prolonged, not equal to the head in length; 

 dorsal subtruncate, none of its rays prolonged; distance of origin of 

 dorsal from caudal 2.6 in the length; origin of anal from base of middle 

 caudal rays 3.75 in the length; caudal emarginate; accessory rays not 

 evident; ventrals not reaching the short, scarcely rounded anal. A 

 dark median band from the gill-opening to the tip of the middle caudal 

 rays, a light stripe above it; the back chocolate. 



The specimens were obtained by Mr. Thomas Barbour at La Paz, 

 Bolivia, from a person who had been prospecting along the Beni 

 River. 



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