I have been requested by Mr. Edwards, who has presented to the Association an interesting and valuable paper, “On the Length of Life of Butterflies,” to supplement it with some remarks on the Life Duration of the Heterocera.

The period of time passed by insects in their perfect stage, is an item in their history to which, so far as I know, very little attention has been paid.

The species belonging to this interesting family have received very little attention from Entomologists generally, and considering the extent of the North American fauna, comparatively few species have been described. Of these almost nothing is known of their habits and development.

EGG—In shape are oblate spheroid, somewhat pointed at base, and little truncated and depressetl at summit ; marked by many horizontal striæ, and longitudinally by 18 or 20 narrow, prominent ribs, which proceed from base and terminate, some of them irregularly, at about four fifths the distance to summit, while eight, increasing gradually in prominence, end abruptly at the rim of the summit ; these long ribs are cut on either side by grooves perpendicular to the surlace of the egg ; they are also frequently deflected somewhat from a direct line; color pale green. Duration of this stage about 4 days.

Hadena perpenoa, n. s.

♂. Eyes naked ; tibiæ unarmed ; abdomen tufted ; size moderate. Apparently allied to Indirecta and Cinefacta, but darker colored, with a certain resemblance to Mamestra Atlantica or Vicina. Concolorous dark wood brown ; lines faint. The usual markings. A dash connects the claviform with the t. p. line.