166 THE CANADIAN ENTOMOLOGIST. 



next to it. In fact the costal fold is a little shorter and narrower than in 

 the other species. This, and the circumstance that in Poggei there is the 

 first intimation of a fold as a narrow seam in the membrane, militates' 

 against the generic separation of Divisions A. and B. 



Poggei, in the form of its antennae, recalls Nisoniades, but the bending 

 of the club does not really begin in the middle, but a little behind it, and 

 it is not so regularly falcate as in that genus. Poggei approaches so near 

 to phlomidis and Proto in all other respects that a separation from them 

 would only be justified if a number of agreeing species could be united 

 to it. 



SCELOTHRIX. 



Club of antennae elongate ovate, somewhat compressed, feebly falcate, 

 rounded on the end. Locklet, palpi and fringe as in Pyrgus. Hind tibice 

 without spines. Male with much developed costal fold ; two membran- 

 ous, sheath-formed appendages on the metasturnum, and a long hair-tuft 

 on the hind tibas. The appendages start from the base of the hind legs 

 and project more or less convergingly, occasionally being bent apart 

 (feebly x-shaped) for nearly one-third the length of the abdomen, over the 

 very deep and long ventral cavity. They are a pair of almost linear, 

 rather flat, membranous, apparently hollow structures, at first sight to be 

 compared with a short, broad sabre-sheath, thickly scaled, and on the 

 front edge and particularly at the tip with longer hairs. Their form, 

 clothing and color present some differences, which probably (but which I 

 have not proven) will afford useful specific characters. 



The tuft of the tibiae, composed of long, fine pencil-like hairs, arises 

 close under the knee of the hind tibiae on the inner side. It is at least as 

 long as the tibiaj, often considerably longer, and appears in captured 

 specimens, generally, spread apart. When drawn in, it is placed under 

 the sheath-like appendages — at least this is so in several specimens in my 

 collection. Its color varies from pale yellow to black in various degrees 

 of mixture. 



This genus approaches so near to the preceding one (several of its 

 species agreeing with it fully in habitus, color and marking) that the 

 separation requires special justification, because the differences become 

 conspicuous only in the male sex. But in this sex the differences are so 

 highly developed and easy to detect, — the forms united thereby so homo- 

 geneous — that it seemed to me more reasonable to establish a new genus 



