318 Annals of the Carnegie Museum. 



large; a broad band of teeth in each jaw; postmental barbels about 

 one-half as long as the maxillary barbels, which extend to the gill- 

 cleft; gill-membranes separate, and joined only to the front edge of 

 the isthmus, as in Lophiosilurus; head covered with skin, without 

 exposed bony ridges; occipital process extending to the dorsal plate; 

 lateral-line organs well developed, as in Lophiosilurus; the anterior 

 portion of the body depressed and the caudal portion compressed; 

 the caudal round; the skin on the dorsal and lateral sides covered 

 with papillae and short hair-like projections; the color above and below 

 brown; many black spots on the sides, back, and fins. 



I take pleasure in dedicating this species to Mr. H. W. Fowler. 



Imparfinis mirini, sp. nov. 



(Plate XLVII.) 



Type. — No. 2981. 8.3 cm. long. Near Piracicaba above the falls 

 of the Rio Piracicaba-mirini, September 7, 1908. 



Cotypes. — Nos. 2982 a-d] 5-7 cm. long. From same place, taken 

 at same date. 



Cotypes. — Nos. 2983 a-c; 5.5-7 cm. long. Same place and date, 

 but from below the falls, which are twenty feet high. 



A. 10; D. I. 6; head about 5; depth 6; eye 2.5 in snout, 2 in the 

 interorbital space, 5 to 6 in the head; caudal portion of body com- 

 pressed; head conical, being almost as deep as wide, and two-thirds as 

 wide as long. No free orbital margin; weak dorsal and pectoral spines 

 with soft tips; mental barbels extending almost to base, and postmen- 

 tals slightly past base, of pectorals; maxillary barbels to, or beyond, the 

 tip of pectorals; ventrals inserted below the middle of dorsal; practi- 

 cally no dorsal plate and very minute occipital process; the adipose is 

 longer than the anal and equals the distance between the dorsal and 

 adipose; caudal forked; color almost uniform light brown, with some 

 dark edges on fins. Two specimens have bases of caudal black and 

 some indistinct blotches on the back. This species is easily dis- 

 tinguished from Imparfinis piperatiis by its conical instead of depressed 

 head. 



This species lives under stones in rapids. 



Imparfinis transfasciatiis (Ribeiro) and Rhamdiaglanis frenatus 

 (R. Von Ihering) are synonyms of Imparfinis piperatiis. 

 I have examined the types of all of these species. 



