WILLOW CATERPILLARS. 573 
though recognizing it in the breeding box, I give the following descrip- 
tion of the larva, which differs somewhat from that on p. 527 (wild cherry 
insects). 
Larva. — Head smaller than usual, rounded; not so wide as the prothoracic segment ; 
body broad, somewhat flattened ; somewhat resembling the figures of Hibernia; in- 
creasing in thickness to the middle, and thence decreasing to the anal legs, which are 
small; supra-anal plate small, much bent down; with six piliferous warts at the end. 
Head amber colored ; body deep flesh, somewhat livid, with a slight broken dorsal 
median dark line and two broad lateral dark reddish brown supraspiracular lines. 
No other markings, and the piliferous warts very small ; beneath reddish flesh-colored. 
Length, 20 mm . 
34. Geometrid larva. 
(Larva, PL v, fig. 8, a, b.) 
Found August 5, on the willow at Brunswick. 
Larva. — Head broad and flat, square on the sides ; as wide as the prothorax ; the 
body very slender, long, cylindrical; remarkably like a slender willow twig, stained 
irregularly with lilac-gray and reddish brown ; a lateral slight swelling on side of 
mesothoracic segment ; two twin dorsal tubercles on end of sixth segment, and a 
large pair on the succeeding ring ; supra-anal plate short, rounded, with two dis- 
tinct piliferous nipple-like warts on the end. Length, 25 mm . 
35. Geometrid larva. 
(Young larva, PI. v, fig. 7, a, b.) 
Several caterpillars of this species occurred in Maine on the willow 
August 6, becoming mature and pupating from the first week in Sep- 
tember to the middle of the month. 
Larva before penultimate molt. — Head large, flattened, as broad as the body, which 
is rather slender, with a pair of subacute mostly blackish warts on the end of each 
abdominal segment, aud a much smaller less conspicuous pair on the front edge ; 
lateral ridge sharp and well marked, especially posteriorly. Head and body 
curiously marbled and stained with pale gray and black-brown ; head marbled with 
a dark diffuse stripe on each side, extending back upon the prothoracic segment ; 
from the sides broad triangular blackish patches extend up, their apices nearly 
meeting on the back at the dark tubercles ; these patches connect with an irregular 
blackish lateral line extending from the base of the thoracic feet along the front edge 
of the anal feet, which are of moderate size and width. Six piliferous warts in a 
straight line across the front edge of the supra-anal plate, which is broad, rounded 
triangular, the surface rough, aud the end washed with black-brown. A dorsal dark 
median line on the front and hinder end of the body, interrupted in the middle. 
Length, 15 mm . 
Mature larva. — With essentially the same characteristics as in the previous stage, 
but more like a dried willow twig; the piliferous warts are large and end in a short 
stiff hair; they are mostly black, pale around the base; the spiracles are ringed 
with black. Length, 40 mm . 
36. Eupithecia sp. 
This caterpillar occurred on the willow at Brunswick, in August r 
and made a slight silken cocoon between the leaves September 3. 
Larva. — Much like that of the Eupithecia on the spruce, the body being of the same 
size and shape ; the surface granulated, and with short stiff hairs; reddish carneous ; 
