MEMOIKS OF THE NATIONAL ACADEMY OF SCIENCES. l63 



Dr. Dyar, in liis account of the Calitbriiiaii iusect. .states tliat '-tlie larv:e turn bluisli and enter 

 the grouiul to pupate, forming' a i-ell lined with sillc." 



Pitpa. — Dark brown. Head case smooth, deeply incised between the abdominal segments. 

 Anal segment large and smooth, the cremaster ending in two short points "projecting almost 

 laterally from the last segment, which, nevertheless, hold to the silken web with considerable 

 tiriniiess. Length, !'<; mm.; width, S mm." (Dyar). 



Food plants. — Feeds on the poplar, aspen, P.alm of Gilead, and willow, both in Maine and in 

 Calitbrnia. 



Ihdiits. — I first found the singular sphinx-like caterpillar of this moth over twenty-five years 

 ago at Brunswick on the Balm of Gilead, September 28. The general color was a purplish lead; 

 head and first segment greenish; the horn on tlie eighth segment black, the dark shade prolonged 

 into a lateral line; a kiduey-sha])ed spot on the last segment; si)iracles black, encircled with white; 

 below a yellow line. Beneath greenish and yellowish straw. October ii it pupated. 



The remarkable larva recalls those of the Sphingidte, and I confess when I first saw it I was 

 uncertain whether to regard it as a Sphingiil or not. The horn is slightly retractile, and thus 

 being movable, must add to its efficiency as a terrifying appendage, while the black streak on 

 the sides heightens the effect of the horn. The spiracles also are so large and conspicuous that 

 it is possible that they may add to a visage not altogether prepossessing to those insects or birds 

 which may desii-e to lie too intimate with it. Many years ago, when a boy, I found this larva on 

 the Balm of Gilead poplar, and well remember the peculiar porcelain polish and lilac tints of 

 the glaucous green skin and the iirominent horn. Dr. Lintner (Ent. Contr., iv, 76) has given an 

 interesting acconnt of this caterpillar, which he found both on the aspen and the willow, and he 

 also at first, as he says, mistook it for some Sphinx larva. 



Dr. Dyar has described (Psyche, Vol. VI, p. 196) at length all the stages (five) of this species 

 (P. dimidiatu H. S.) from California, wheie it feeds on poplar and willow. His larva; were found 

 iu the Yoseniite Valley, California, and he says that in that region there are two broods a year, 

 the winter being passed in the pupa state. (In New York there seem to be also two broods, from 

 the statement of Mr. Tepper, given below.) It seems to differ in Stage I from the normal form in 

 the eighth abdominal segment having "a single large dorsal dot instead of row 1, but it bears two 

 setffi" (p. 351). 



In ]Maine I observed the eggs and freshly hatched young on the underside of the leaves of 

 the aspen the 2(\t\i of July and 1st of August. The female lays usually three eggs near together 

 on a leaf. The larva does not appear to eat them np, as the eggs are found throughout the 

 month, with simply the hole gnawed by the larva in making its exit. The young larva is solitary, 

 and eats a patch on the underside of the leaf. The larva in the second and later stages were 

 unusually frequent iu Maine in 1800. 



The larva has been described by Jfr. C. F. Goodhue, who has found it on the poplar and 

 willow in New Hampshire late in September. "The transformation tfikes place in a slight cocoon 

 of dead leaves fastened together with a few silken threads, on the surface of the ground, much in 

 the manner of Durupsa myron." The moth api)ears in S])ring, as well as in August: it occurs 

 throughout the Eastern and Middle States. 



Mr. F. Tepper has raised the caterpillar which occurred on the willow in New York June 22; 

 it went under ground a few days after, and the moth emerged .Vugust 22. 



• Geofp-aphical distribution. — Occurs in the Appalachian and Campestrian subprovinces. Orono, 

 Me. (Mrs. Fernald) ; Brunswick, Me. (Packard) ; New Hampshire ((roodluie) ; Amlierst, Mass. (Mrs. 

 Fernald); Albany, N. Y. (Lintner, Meske); Plattsburg, N. Y. (Hudson); Seattle, Wash. (Johnson); 

 Victoria, British Columbia (Neumoegeii). 



Var. portlandiu, Portland, Oreg. (Behreus, Dyar); normal form Chicago, 111. (Westcott) ; 

 Racine, Wis. (Meske); Colorado (U. S. Nat. Mus.); Alaska. Maryland. Colorado, Ohio, and 

 Nebraska (U. S. Nat. Mus.); Canada, Maine, New Hampshire. Massachusetts, Rhode Island, New 

 York, North Carolina, Los Angeles, Cal., ]\[ichigan (Cook, Mus. Comp. Zool.); Fort Collins, Colo., 

 June 20, at light (Baker); New Jersey, Pennsylvania, Nebraska (Pahu). 



