OP WASHINGTON, VOLUME XII, 1910. 169 



Genus TROSIA Hubner. 



Trosia Hubner, Verz. bek. Schmett., 196, 1816; type, tricolora 



Fabricius. 

 Sciathos Walker, Cat. Lep. Het. Brit. Mus., iii, 752, 1855; type, 



punctigera Stoll. 

 Endobrachys Felder, Reise Novara, pi. 83, fig. 17, 1874; type, 



revocans Felder. 

 Isochroma Felder, Reise Novara, pi. 83, fig. 18, 1874; type, fallax 



Felder. 



The typically marked species of Trosia are very distinct, 

 with red abdomen and hind wings and row of dots across fore 

 wings. There are three rather common and widely distributed 

 species, but their nomenclature is much involved. The larg- 

 est species-has the fore wings white in the male, overspread 

 with a gray and rosy shade beyond the cell. The wings are 

 produced, the inner margin being nearly parallel to the costa. 

 This is punctigera Stoll. The other two species have the 

 wings more trigonate and uniformly colored. In one (dtmas 

 Cramer), the wings are white, in the other (misda Schaus) 

 they are ocher yellow. Several variations of the type occur, 

 of which incostata Schaus, without the costal stripe, rosci- 

 puncta Druce, with the spots red, and albida Dognin, with the 

 hind wings white, are before me. 



The second group of Trosia is composed of a number of 

 white species such as nigripes Dyar,pitreiis Schaus, and parr a 

 Schaus, that look like species of Xorape and are probably 

 closely allied to that genus, but the venation is still too gen- 

 eralized to allow of their inclusion in that genus. 



The third group consists of one species, acca Schaus 

 (== ribbei Druce), with red body and hind wings, the fore 

 wings rather thinly scaled, brown, with the veins indicated in 

 darker color. 



The fourth group {Endobrachys Felder) has the wings 

 much elongated, the coloration of longitudinal shadings. 

 This is obviously derived from some such form as punctigera 

 in the first group. 



The fifth group comprises habitus Hy. Edwards (== contigua 

 Walker, according to Druce) and gamelia Druce. These 

 species are aberrant in the genus, but the presence of a distinct 

 frenulum excludes them from Megalopvge. 



