24 ZYGCENIDiE AND BOMBYCIDiE 



middle. Wings broad; the primaries a little less than half as broad as 

 long. Costa full, convex towards the apex, which is rounded acute. 

 Outer margin half as long as the costa, more than usually oblique. 

 Inner edge two-thirds as long as the costa. The costal area is very 

 narrow in this genus, since the subcostal runs very near the edge of the 

 wing, and its first, second and third nervules are very long and parallel 

 to the costal edge. Third subcostal simple, the fourth arises midway 

 between the apex of the wing and the origin of the second subcostal. 

 Fifth slightly removed towards the middle of the discal area, arising 

 directly opposite the first and second median nervules, the origins of 

 which are united, the second being straight, while the first and third 

 are arched, the last one named arising very near the two first. They 

 then enclose a very regular semioval area. Fourth median arises at a 

 distance from the third equal to the length of the two discal nervules, 

 which are straight, and unitedly are directed exactly at right angles to 

 the costa. 



' ' The secondaries are broadly triangular, reaching nearly to the tips. 

 The costa is decidedly convex within its middle; the apex is produced, 

 but very much rounded, as in the internal angle, though the inner edge 

 is itself very straight, and is one-half as long as the costa. The lower 

 discal nervule is directed obliquely outward, and both are curvilinear. 

 The space between the first and third median is acutely triangular, 

 since the nervules are nearly straight. 



"The legs are long and slender, the hind tibiae with two pairs of 

 small acute unequal spurs, of which the inner pair are the smaller. 

 Hind tarsi longer than the hind tibiae, and the first tarsal joint is a 

 little shorter than the three succeeding ones taken together. Abdomen, 

 twice the length of the thorax, provided with minute lateral tufts, slowly 

 tapering towards the tip, which is subacute, though not abruptly pointed." 



Packard, Proc. Essex Inst., April, 1864. 



The colors of the genus are bluish black or brown on the primaries, 

 which are usually concolorous, but occasionally have the veins of a dif- 

 ferent hue, and deep blue black on the secondaries, with more or less 

 Vermillion or yellow on the head, collar and epaulettes. The general 

 size of the insects is about two inches across the win^s. 



