1886.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 417 



wardly bent over the luniile. This lunule consists of a narrow vitreous 

 crescent obliquely crossing the median cell, its horns touching the 

 transverse lines. The convex upper margin is black, the concave por- 

 tion is broadly shaded with yellow. At the apex is a large irregular 

 lilac blotch, outwardly limited by a narrow irregular white line, at the 

 lower end of which is a large round black spot, with a narrow whitish 

 lunule near the inner edge and a few yellow and lilac atoms. Through 

 the luteousgray outer margin runs a fine dark line, black nearest to 

 apex, fuscous below. Secondaries with an inwardly convex whitish lilac 

 band at base, which at the costal margin connects with a rather acute 

 curve, with an outer band of the same color, and which runs from the 

 middle of the costal margin in two gentle curves to the hind angle. 

 The band is shaded similarly to those of primaries. A strongly curved 

 lunule crosses the cell at the end, its outer upper horn touching the 

 outer baud. The space beyond the posterior transverse line is not so 

 bright in color as in the primaries, and is outwardly limited by a nar- 

 row, somewhat irregular yellow line, followed by a broad irregular dusky 

 baud, and then by two narrow dusky lines, the outer one at base of the 

 fringes, iieneath, the maculation of the upper side is reproduced, save 

 that the basal pale bands are lacking and the color is somewhat paler. 

 Head and thorax like primaries. Head with a white tuft between and 

 at sides of antennae. Thorax with a narrow white line on collar and a 

 broad white band at base. Abdomen yellow, with a basal white band, 

 a crest of white hair on dorsum, a row of white tufts on each side of the 

 middle; a geminate white line, margined with black, inclosing the stig- 

 mata, and two ventral white lines; last segment all white. The body 

 and legs are also white marked. The palpi are small, scarcely reaching 

 the front. The 9 autennai with the pectinations even to the tip, but not 

 ciliate, the branches well separated at the joints. The supra-anal plate 

 of the S is broad at base, narrowing toward the tip, and then divided 

 into two divaricate prongs. 



The larva of this species has been well described by Riley and 

 figured iu the 4th Mo. Kept., and the caterpillar is so well known that 

 it is hardly worth while to describe it again. Its natural food plant 

 is Ailanthus glandulosa, but it feeds also on Eicinus and " will feed and 

 flourish on lettuce, chicory, willow, and teasel" (Riley). Other recorded 

 food plants are tulip tree (Hulst), sheep berry, wild cherry, and bitter- 

 sweet (Van Nostrand). 



The color characters above given are not absolute. An average 

 specimen is described, but the species varies from a bright, almost 

 ocher yellow to a i)ale greenish-clay color. The violet or lilac is also 

 variably intense, and the lines vary somewhat. The insect is, however, 

 so characteristic that there is no mistaking it. The cocoon is spun in 

 a leaf and fastened to the twigs which in Ailanthus drop in the fall. 

 The moths emerge in the latitude of New York late in June or early 

 Proc. N. M. 86 27 December 7, 1886. 



