408 Annals of the Carnegie Museum. 



15. Luciopimelodus platanus (Giinther). 



6995c, C. M., one, 91 mm., to base of caudal, Rio Jauru, emptying 



into Paraguay. 

 7240a, C. M., one, 206 mm., Asuncion, March 31, 1909. 



In the smaller specimen the eye is four times in the head; the inter- 

 orbital five times; the snout a little longer than the postorbital part 

 of the head; maxillary barbel extending to the end of the adipose. 



16. Platysilurus barbatus Haseman. 



7244a, C. M., one, 98 mm., Rio Mamore, Sept. 19, 1909. Haseman. 

 7245c, C. M., one, 155 mm., Manaos, Nov. 28, 1909. Haseman. 



The measurements are the length of the fish without the caudal 

 filament, which in the case of the larger specimen is 160 mm. long. 



Imparfinis Eigenmann & Norris. 



This genus differs from Rhamdella principally in the non-develop- 

 ment of a dorsal spine, the pectoral spine being also weak. It scarcely 

 dififers from Chasmocranus, in which there is no trace of a free orbital 

 rim, while in the older specimens, at least of Imparfinis piperatus, 

 there is a distinct free orbital margin. There is no free margin in 

 /. minutus or in I. mirini. The head in Chasmocranus is extremely 

 ■depressed. 



17. Imparfinis piperatus Eigenmann & Eigenmann. 



7257C-&, C. M., two, 1 10-126 mm., Morretes near Paranagua, Jan. 4, 



1909. Haseman. 

 7259c-/, C. M., six, 68-222 mm., Cubatao, west of Santos, Aug. i, 



1908. Haseman. 

 7260a, C. M., one, 173 mm., Agua Quente, emptying into Rio Ribeira 

 ■da Iguape, Nov. 27, 1908. Haseman. 

 726ia-&, and 6928a, C. M., three, 63-214 mm., Raiz da Serra, Rio 



Mogy, flowing into Santos Bay, July 26-28, 1908. Haseman. 

 6930a, C. M., one, 87 mm., Iporanga, Ribeira da Iguape, Dec. i, 1908. 



Haseman. 



These are very similar to miniita. The head is more depressed, the 

 pectorals do not reach the ventrals, the maxillary barbels reach the 

 middle of the pectoral in the smaller specimens, and are one and four- 

 tenth times in the head in the largest. The caudal is shorter, the 



