March, i9i7-] Ji^RBES : HydRIOMENIN.E OF THE UNITED StaTES. 59 



25. Prout in the " Macrolepidoptera of the World" divides this 

 group as follows, but the differences are not very wide. The whole 

 group has been generally called Polythrena in the old world. 



Middle discocellular of hind wing angulate. 



One ace. cell, no pencil on hind wing; black and orange {Polythrena). 



coloraria, miegata, angularia (Asia). 

 Two ace. cells, a pencil on upper side of hind wing as well as under side 



of fore wing; black and white {Trichobaptria) exsecuta (Asia). 



Middle discocellular short and straight, one pencil only ; black and white 

 (Trichodesia) . . . .albovittata, calif orniata, haberhaueri, kindermanni. 

 The typical group makes the transition to Eustroma. 



26. True Eustroma, characterized by Prout as having the pencil 

 of hairs arising below A> and the apex of the wings more rounded, 

 does not appear to occur in this country. Atrocolorata has the proper 

 type of markings, but has no trace of the hair-pencil. Photoscotosia 

 (Lasiogma) approaches our nubilata, but seems to differ in the short 

 straight mdcv. Neolexia and Phylace are parallel developments from 

 slightly different groups of Lygris; Phylace has the hair-pencil but it 

 is not very strong. Our species may be grouped as follows : 



Male antennae bipectinate. 



Hair pencil normal, markings of triangulatum {Neolexia) xylina. 



Hair pencil weak, markings of populata group {Phylace) luteolata. 



Male antennae laminate or more or less serrate; pencil normal {Lygris). 



Pencil massive, a third the length of the inner margin or more, habitus of 



Oriental species of Eustroma cunigerata. 



Pencil moderate in size triangulata (prunata auct.), destinata. 



(Is this distinct from the last?), testata, remotata, populata, diversi- 

 lineata and the European prunata, pyropata, associata, etc. 

 Male antennje laminate, pencil forming a long black streak nubilata. 



The last group is possibly transitional to Photoscotosia. 



27. T. dubitata does not occur here ; our species with strikingly 

 distinct genitalia, but almost identical markings is iiidubitata Grt. 

 Progrcssata Walker seems to be a West Indian Coryphista, the 

 western species must become pustnlaria, and its smooth black form is 

 nameless. The difference between it and the eastern form is slight. 

 Calif orniata (packardata Gross.) seems to come here, but is a strik- 

 ingly distinct species. 



28. Seems to differ from Hydriomena only in the male antennas, 

 certainly not sufficient to base a subfamily on. The wing-form and 

 pattern agrees with Ortholitha. 



