MEMOIRS OF TQE NATIONAL ACADEMY OF SCIENCES. 103 



Dr. Dyar, in his accoiiiit of tlie Calilbriiiiiti iuseot, states that "the larva' turn bhiish and enter 

 the ground to pupate, forming a eell lined with silk." 



riipii. — Dark brown. Head case smootli, deeply iueised between the abdominal segments. 

 Anal segment large and smooth, the cremaster ending iu two short points ''projecting almcst 

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

 firmness. Length, 2(1 mm.; width, 8 mm." (Dyar). 



Food plants. — Feeds on the poplar, aspen. Balm of (lilead, and willow, botli iu Maine and in 

 California. 



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

 ago at Brunswick ou the Balm of Gilead, Septeaiber 28. The general color wa.s a puri)lis!i lead; 

 Lead and first segmeut greenish: tlie horn on the eighth segment black, the dark shade prolonged 

 into a lateral line; a kidneyshai)ed spot on the last segment; spiracles black, encircled with white; 

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



The remarkable larva recalls those of the Sphingid;e, and I confess when I first saw it I wa.s 

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

 being movable, must add to its etticiency 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 uot altogetlier prepossessing to those insects or birds 

 which may desire to be too intimate with it. Many years ago, when a boy. I found this larva oa 

 the I>alm of Cilead poplar, and well remember the peculiar porcelain polish and lilac tints of 

 the glaucous green skin and the prominent horn. Dr. Lintuer (Ent. Contr., iv, 70) has given an 

 interesting accouTit 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. 190) at length all the stages {i\\ii) of this species 

 [F. dimidiatd H. S.) from California, where it feeds on poi)lar and willow. Ilis larvae were found 

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

 the winter being passed iu the pupa state. (In New York there seem to be also two lii-oods, from, 

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

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

 seta^" (p. 351). 



In Maine 1 observed the eggs and freshly hatched youug on the underside of the leaves of 

 the aspen the 2()th 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 up, as the eggs are found throughout the 

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

 and eats a i)atch ou the underside of the leaf. The larva in the second and later stages were 

 unusually frequent iu Maine in 18!l0. 



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

 willow in New Hampshire late in September. "The trausforniatiou takes 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 Darap.sd mijron." Tlic moth appears iu sjiring, 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 August 22. 



Geographical distribution. — Occurs in the Appalachian and Campestrian aubprovinces. Orono, 

 Me. (Mrs. Eernald) ; Brunswick, .Me. (Packard) ; New Uampshire (Goodhue) ; Amherst, Mass. (^Irs. 

 Fernald); Albany, N. Y. (Lintuer, Meske); Plattsburg, N. Y. (Hudson); Seattle, Wash. (John.son); 

 Victoria, British Columbia (Neumoegen). 



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

 Kacine, 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 Cai'olina, Los Angeles, Cal., Jlichigan (Cook, ^Mus. Comp. Zool.); Fort Collins, Colo., 

 June 20, at light (Baker); New Jevsey, Peunsylvauia, Nebraska (Palm). 



