182 CALIFORNIA ACADEMY OF SCIENCES. 



Anal emarginate, the last ray longer than the three 

 rays preceding it, the fourth ray longest. 



Ventrals equal the head in length; reaching about 

 beyond the vent; distance from vent to anal longer than 

 head; the head 2J in the distance from the vent to the 

 caudal. 



Pectoral spine flat and curved, roughened near its 

 middle in front, strongly recurved hooks its entire 

 length behind; its length 1| in head. 



Depth of caudal peduncle 2J-3 in head. 



Color plain greenish; tips of dorsal dusky. 



Head 5; depth 4 to 5J; Br. 7; D. I, 6; A. 11. 



130, Pimelodus fur, 



Pseudorhamdia fur (Keinhardt MS.) Liitken, Dan. Viden. Selsk. 



1874, 33 (Kio das Velhas); Liitken, Dan. Selsk. Skr. 169, plates 



ii and iii, fig. 3, 1875. (Kio das Velhas). 

 Pimelodus fur Eigenm. & Eigenm., Proc. Cal. Aead. 2d Ser. i, 135, 



1888 (Rio das Velhas; Giquitiba; Rio San Francisco). 

 Pimelodus maculalus Kner, SB. Ak. Wien, xxvi, 413 (Irisanga; Rio 



Branco; Barra do Rio Negro); in part. 

 Pimelodus microstoma Steindachner SB. Ak. Wien. Ixxiv, 1876, 



Siisswasserfische siidostl. Bras, iii, 44, foot note (Irisanga; Rio 



Branco; Barra do Rio Negro). 

 Habitat: Amazon, Rio San Francisco and its tributaries. 



We are unable to distingush Pimelodus microstoma 

 from the specimens of P. fur in the Museum. The 

 specimens examined are soft and their depth is not as 

 given by Liitken and Steindachner. They are from the 

 Rio das Velhas and Giquitiba on the Rio San Francisco. 



Body slender, compressed towards the caudal; head 

 conical, scarcely wider than the body; its width 1| in 

 its length; its depth, at the posterior margin of the eye, 

 2 in its length; profile regularly curved from the dorsal 

 spine to the snout; head convex in tranverse section. 

 Occipital crest triangular, longer than wide, entirely 

 covered with thin skin; fontanel not extending to oppo- 

 site posterior margin of eye; a small groove or pit at the 



