MEMOIUS OF THE NATIONAL ACADEMY OF SCIENCES. 127 



abdoiniual segments are of the same color, but tlie other pilifeious dorsal warts are yellow. There 

 are four parallel whitish gray dorsal lines, or rather three darlc, livid-brown, fine dorsal lines 

 on a grayish white field. 



Laat stage (PI. XY, fig. 1). — Length, lio mm. Head brown black, tlattened, as wide as the body ; 

 ■with gray hairs. The prothoracic plate is widely divided into two transversely oval brown-black 

 plates. The body is marked with a broad, dorsal, ash-gray band, containing three vandyke brown 

 more or less broken lines. The sides of the body darker aud containing two darker, irregular, 

 broken lines. On the first thoracic segment are no dorsal yellow warts, but two on each side, the 

 ui)per one in front of the spiracle, button like, prominent. On the second and third thoracic; 

 segments are four yellow tubercles, forming a transverse series. On the second to eighth abdom- 

 inal segments the yellow warts are arranged in a very low trapezoid, and the two anterior ones 

 are minute. Tliose on t!ie ninth segment form a cnr\cd line. The suranal plate is broad and 

 rounded, speckled with black. There are no humps or specialized waits on the first and eighth 

 abdominal segments, thus differing from the larva of I. indusH. The thoracic legs are blackish; 

 the abdominal and anal legs livid ash. 



The larva differs decidedly from that of /. iiichisa, though the moth is nearly allied. 



The moth bred from this caterpillar is of the dark mouse-colored Ibrm, normal, usual in Maine 

 aud Franconia, N. U. One like it from Illinois is iu my collection. 



The following description is of a larva reared in Maine from eggs received from Mr. ^Yiley. 

 of Miles City, Mont., aud, as Dr. Dyar states, is '-the pale ^Yestern form," aud perhajjs var. 

 astorifv (Edw.). 



Life history of var. ornata subvar. astoriw (PI. XY, figs. 2, .'^). — The eggs were kindly sent me 

 by Mr. C. A. Wiley, of Miles City, Mont.; they were deposited on the willow May 24. IS'Xi, and 

 were received June 5, but the larva had hatched out and must have been feeding several days, as 

 the body was tilled out, the head not being quite so wide as the body. The larv;e feed on the 

 underside of the leaf, and if transferred to the upper side walk back beneath. 



Ejifi. — Diameter, 0.7 mm.; hemisi)herical or flattened conical, moderately high, very broad, 

 broader than high; the surftice not regular, having au irregular meridional swollen portion, the 

 top being somewhat swollen. The surface is pitted as seen under a lens. Lender a one-half inch 

 objective it is divided into slightly convex polygonal areas, with definite thin raised edges. 



The hole eaten by the larva for its exit is characteristic, being round, with the edge 

 crenulated, each concavity representing the incision made by the jaws; in some cases the disk cut 

 out is connected by a stalk with the side of the hole. 



Larva, Stage L. — Length, 4 nun.; head black; body long and fidl, with the segments rather 

 full and convex, especially on the sides, particularly on the sides of the third abdominal segment. 

 The first and eighth abdominal segments f idler, more convex than the others, and dorsally sicollen, 

 almost humped, and dnll darh varnish or pitchu red, causing them to he very distinct in appearance 

 from the other abdominal segments. Along the sides of the body is a broad longitudinal band of 

 the same pitchy red hue; it is most distinct aud continuous on the abdominal segments, but 

 divided into two broken lines on the upper edge, aud it is a little broken on the three thoracic 

 segments, where it is most emjjhasized on the swollen sides of each segment, and wanting in the 

 sutures between the segments. The body is greenish yellow, and iu the dorsal yellow portion 

 of the back are three faint broken parallel equidistant dorsal lines. On the side of the body 

 low down are three broken reddish brown lines, the lower one the broadest, and passing along 

 the base of the abdominal legs. The hairs are of unequal length, whitish. Prothoracic plate 

 short aud wide, black, distinct. Suranal plate broad, short, triangular, black. Thoi-acic legs 

 blackish; abdominal legs (including the anal ones) pale greenish, the color of the body, but with 

 a dark cliitiuous callosity on the outside just above the plauta. 



The larva molted June 14- Lj. 



Stage IT. — Length. 8-11 mm. Head tlattened, small, not so wide as the body. A short, broad, 

 dark brown prothoracic shield, not interrupted in the middle. The first and eighth abdominal 

 segments decidedly swollen above, almost humped; the color chocolate-brown, and concolorous 

 with the broad lateral band, which incloses two faint, pale, broken lines, and is often broken 



