450 EIGENMANN 



Rhamdia quelen Qiioy & Gaimard. 



One specimen. 

 Pimelodus clarias macrospila Giinther. 



Two specimens, each with 3 series of large spots. 

 Pimelodus albicans Valenciennes. 



One specimen. 

 Pimelodus valenciennis Kroyer. 



Four specimens. 



Iheringichthys labrosus (Kroyer). 



Several specimens. 

 Doras granulosus Valenciennes. 



A single specimen, 470 mm. long. 



Lateral line 22, the hooks of the lateral plates beginning 

 under the end of the dorsal. 



LORICARIID^ 

 Plecostomus commersoni Cuvier & Valenciennes. 



Four specimens. 

 * Plecostomus laplatae Eigenmann, new species. (Plate XXI.) 



Depth 5 in length; head 3.4 (3.28 in cotype) ; D. 1, 7 (not 

 counting the fulcrum); A. 1, 4 ; scutes 31 -f 1 caudal scute; 

 depth of head 1.75 (1.66) ; width of head 1.2 in its length (1 + ) ; 

 length of snout equaling depth of head (1.5 in head); inter- 

 orbital 2.8 in head (2.66); length of mandibular ramus 3 in 

 interorbital (2 + ) ; barbel more than half length of eye; snout 

 spatulate, rounded ; supraorbital margin not raised ; supraoccip- 

 ital ridge very feeble, temporal plates not carinate ; scutes of 

 sides little keeled, spinulose, 7 between dorsal and adipose, 14 

 to 16 between anal and caudal ; supraoccipital bordered by a 

 median and two or three lateral scutes. Lower surface of head 

 and belly entirely granulose in the type, partly naked between 

 the base of pectoral and ventral. First dorsal ray about equal 

 to length of head, last ray .66 (.5) length of head ; base of dor- 

 sal equal to its distance from end of second scute beyond tip of 

 adipose spine ; pectoral extending to second sixth of the ventrals ; 

 caudal distinctly emarginate ; caudal peduncle a little more than 

 3 times as long as deep. 



