8 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 123 



the lateral lobe of the uncus is a most useful distinguishing character; 

 in C. atrox the posterior projection is beaklike in shape and arises 

 from near middle of distal margin. Eighth tergite (fig. 2a) incised 

 more shallowly along posterior margin than in C. keta, not distinctly 

 enlongated anteriorly and with posterior lobes blunt. 



Female (pi. 2: figs. 2, 3). — Forewing above dark brown in the 

 outer one-half of wing, dull metallic purple on the basal one-half. 

 Hindwing entirely dull metallic purple except for indistinct dark 

 brown marginal spots in anal area below vein Cui and a white marginal 

 line extending from anal angle to vein M 3 . Orange-red spot on anal 

 lobe faintly indicated. Wings underneath entirely like the male 

 except for a smaller black center in the marginal ocular marking on 

 interspace Cui. 



Length of forewing 12 mm. 



Female genitalia as illustrated by figure 13 with ductus bursae and 

 bursa copulatrix relatively short, their combined lengths being about 

 three and one-half times the width of the superior genital plate; the 

 latter with free edge a long continuous ridge having lateroposterior 

 angles that are projected slightly and bluntly. 



Type-locality. — "Pedroso, Rio Purus, State of Amazonas, Brasil." 



Additional type data. — Described by Butler from a single speci- 

 men, the holotype, male (Sept. 25, 1876, James W. H. Trail), now in 

 the collection of the British Museum (Natural History) and labeled 

 with type number "Rh. 911" and with male genitalia preparation 

 number "R. 1951 NHB 493." This holotype is illustrated by figures 

 1 and 2 on plate 3. 



Location of type. — In the British Museum (Natural History). 



Method of identification. — A topotype was not available for 

 comparison with the holotype; however, a specimen from French 

 Guiana was found by D. S. Fletcher that is identical in habitus and 

 genitalia with the type. Through the courtesy of A. G. Gabriel the 

 compared specimen was sent to me for study and, together with the 

 photograph of the type (pi. 3: figs. 1, 2), is the basis for the present 

 identification. 



Distribution.— In widely separated localities in British Guiana, 

 French Guiana, Brazil, and Peru. 



British Guiana: Demerara County, Wismar (December). French Guiana: 

 Colony of Guiana, St. Laurent (no date). Peru: Department of Loreto, Rio 

 Morona (6003 ft., January). Brazil: State of Amazonas, Pedroso, Rio Purus 

 (September). 



Material studied. — Five males and one female, including their 

 genitalia. 



