448 William T. M. Forbes 



29. OLETHREUTES Hiibner 



(Argyroploce; Penthina; Sericoris; Eucosma, in part, etc.) 



Palpi porrect (fig. 281), clavate or triangular, with short porrect third joint. 

 Thorax tufted behind; fore wing smooth or with slight tufts or ridges at end 

 of cell and near base of inner margin. Fore wing (fig. 266) with all veins free 

 and well spaced at the margin, which is evenly rounded, M 2 a little spaced from 

 M 3 and Cu 1 at origin; no costal fold. Hind wing with R and M x approximate or 

 stalked; M 2 distinctly separate from M 3 , but rarely as widely as in Laspeyresia 

 (0. liebesana) ; M 3 and CUj connate, rarely stalked, or very slightly separate. 

 Inner margin in male thickened and variously folded or rolled up; sometimes with 

 a lobe as in Exartema, but if so, with the lobe concealed in the fold, and quite 

 small; usually with' a hair pencil. Xo thickening or dense scaling except on dor- 

 sal margin. Hind tibia of male with a hair pencil arising from base (rather 

 fragile, and lost in rubbed specimens) but without long dense hair. Rarely, the 

 dorsal fold or tibial hair pencil are rudimentary, but never both in the same 

 species. 



This is a large and well-defined genus (at least in the male) from which Phse- 

 casiophora is derived; it is closely related also to- Cymolomia and, to judge 

 by the occasional occurrence of a free lobe on the inner margin, is perhaps derived 

 from it; more probably it is heterogeneous, composed partly of older and partly 

 of newer species than Cymolomia. Bactra is also considered related, but lacks 

 the thoracic tuft. The male is easily distinguished ; the female is like that of 

 Cymolomia and Phaecasiophora, but can be distinguished from other genera by the 

 combination of tufted thorax, practically smooth wings, approximate R and M l3 

 and M = shortly but distinctly separate from M 3 and CUj. Ecdytolopha and 

 Gymnandrosoma have nearly the same combination of characters, and are united 

 to it by Walsingham and Durrant, but M 2 is more widely separated, the palpi are 

 smooth, and the general appearance is different. 



Key to the species 



1. Fore wing dark, with moderate, clearly-defined white costal patch. 



2. Patch a third the length of the wing, its edge sharply defined and even. 



33. chionosema. 

 2. Patch less than a quarter length of wing, irregular or diffuse on the lower 

 outer side. 



3. Patch pink . . . 31. roseomaculana. 



3. Patch white 32. costimaculana 



1. Fore wing whitish with dark shade toward middle of costa 30. albeolana. 



1. Median area evenly yellow, contrasting. 



2. Outer part of wing almost evenly purple-black 39. ochromediana. 



2. Outer part of wing with darker, pale-defined patches ("Cymolomia pat- 

 tern " ) 38. osmundana. 



1. Median area with a large, evenly colored patch of greenish or olive-gray. 

 2. Patch on inner margin, between two black patches. 



3. Base and middle of costa pale 35. griseoalbana. 



3. Base and middle of costa blackish 34. impudens. 



2. Patch not resting on inner margin; outer part of wing deep rose. 



36. malachitana. 

 1. Ground yellow and yellow-brown or yellow-brown and black-brown, separated 

 by brilliant blue metallic lines or series of dots. 



2. Ground two shades of dark brown; small ( 12 mm.) 19. coronana. 



2. Paler portion of ground ochre yellow; large (18 mm.) 



