XIII. ON SOME SPECIES OF RHAMDIA, A GENUS OF SOUTH 

 AMERICAN SILURID^, IN THE CARNEGIE MUSEUMS 



By Carl H. Eigenmann and Homer G. Fisher. 

 (Plate XXXVIII.) 

 Genus RHAMDIA Bleeker. 



I. Rhamdia pentlandi (Cuvier & Valenciennes). 



72800-7, C. M., 51-105 mm., Rio Perene at its source. 1909. Lola 



Vance. 



Adipose 4-4.5; maxillary barbel to, or nearly to, origin of anal. D. 

 1.6; A. 12-15; pectoral spine a little longer than the snout, the outer 

 hooks much the stronger. 



2. Rhamdia sapo (Valenciennes). 



72850-^, C. M., Porto Alegre, July 19, 1909. J. D. Haseman. 



Dorsal 1.7 in two specimens, 1.8 in one; eye 6-6.5; interorbital 5.4 

 in the head in the smallest, 3.5 in the largest specimen. The maxillary 

 barbel reaches to near the end of the adipose in the smallest, to the 

 adipose in the middle-sized specimen, and a little further in the largest. 

 The premaxillary teeth are 5.5 times as wide as deep. 



3. Rhamdia microps sp. nov. (Plate XXVIII.) 

 72830-^^, C. M., 111-175 mm., Uruguayana, Feb. 7, 1909. Haseman. 



The largest specimen is the type. Head 3.4-3-5; depth 4.5-5. 

 D. I, 7 in one, i, 8 in three. A. 11-13. Eye six times in the length 

 of the head in the smallest, seven and one-half times in the largest; 

 interorbital three and one-half in the smallest, three in the largest; 

 maxillary barbel reaching beyond base of middle caudal rays on one 

 side of the smallest, to or beyond base of adipose in the largest; adipose 

 fin a little over three times in the length; pectoral spine equals snout 

 and eye in the largest example; dorsal spine three and one-half times 

 in the length of the head in the largest. Pores of the head prominent 



1 Contribution from tlie Zoological Laboratory of Indiana University No. 148. 



394 



