1891.] SILUROID FISHES FROM BRAZIL. 233 



3. PiMELODUS MACULATUs, Lacep. 



4. PiMELODUS (Rhamdia) HILARII, C. & V. 



5. PiMELODUS (PSEUDOPIMELODUS) COTTOIDES, Sp. 11. (?). 



(Plate XXV. fig. 2.) 



D. 1/6. A. 9-10. P. 1/.5. 



Head naked above, a little broader than long ; occipital process very 

 short, in contact with the basal bone of tlie dorsal spine, and two fifths 

 the length of the latter ; length of the head nearly one fourth of the 

 total (without caudal); eye very small, hardly half as long as the snout; 

 maxillary barbel extending to the middle of the pectoral spine, outer 

 mandibular extending as far as the maxillary, mental a little shorter. 

 The band of prsemaxillary teeth of moderate breadth, without pro- 

 longed lateral portion. Pectoral spine very stout, very strongly 

 serrated along its inner, less so along its outer edge ; humeral process 

 strong, half as long as pectoral spine. Distance between end of snout 

 and dorsal spine one third or two fifths of total length (without caudal) ; 

 dorsal fin considerably deeper than long ; adipose fin as long as 

 dorsal, separated from it by a space not quite twice its length. Depth 

 of body one fourth total length (without caudal). Caudal emarginate. 

 Handsomely marked dark brown and pale reddish brown above, the 

 latter colour forming a band across the nape, a spot on each side of 

 the body, below the middle of the dorsal, a broad band behind the 

 dorsal, an oblong spot in front of the adipose fin, and a band round 

 the tail, involving the end of the adipose fin ; dorsal fin dark brown, 

 with a whitish spot occupying the basal half of its posterior moiety ; 

 pectoral dark brown, with a small basal whitish spot ; anal whitish 

 in the middle, crowded with dark brown spots at the base and in its 

 distal moiet}' ; ventrals whitish at the base, crowded with dark brown 

 spots on the remainder ; caudal whitish, with a distal crescentic band 

 of closely-set dark brown spots; barbels annulate with black; lower 

 parts pale brown, marbled with dark brown. 



Total length 92 milUm. 



Two adult and several young specimens from the Camaquam 

 River. 



I should have referred these specimens to Valenciennes's P. c/tarus 

 but for the fact that it is identified by Steindaclmer with P. hufonius, 

 C. & v., a species with a very different dentition. The nearest ally 

 of P. cottoides would then be Pseudopimelodus paraliibce, Stdr., 

 with which it is possibly identical. The proposal of a new name is, 

 however, justified, even should the two species be the same, as the 

 name paraliibce is preoccupied in the genus Pimelodus for a species 

 of the subgenus Rhamdia (R. parahibee, Stdr.). 



6. Heptapterus mustelinus, Val. 



Numerous specimens, from 42 to 220 millim. They vary greatly, 

 irrespective of size, in the elongation of the body, the length of the 

 head being contained from five times and one third to six times and 

 a half in the total (without caudal). The number of anal rays varies 

 from 19 to 23. 



