866 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



them up, waiting to see whether or not they were simpl^^ dead fir-leaves ; 

 in some cases the caterpillars themselves answered the question by 

 walking off at their peculiar measuring gait. 



The caterpillar changed to a chrysalis August 25 ; the pupa appearing 

 September 7, at first greenish, became pale mahogany brown. Length 

 6™™. It was frequentl^^ observed on Finns strobus in August. 



Larva. — Feeding iu August on the leaves of the fir and very closely mimicking the 

 reddish partly dead leaves or needles ; a measuring or inch worm, with the body flat- 

 tened from above downward and tapering at both ends, thus closely approximating 

 the form of the fir-leaf. Head small, narrower than the body ; smooth, pale, mottled 

 and spotted with reddish. Body reddish, covered with fine whitish papillae ; a faint 

 blackish, somewhat broken narrow dorsal line; a fine pale whitish subdorsal line. 

 Lateral line yellowish in partly grown caterpillars, obsolete in larger ones, becoming 

 distinct on the sides of the not large sharply acute supra-anal plate ; two large acute 

 spines below the plate. Body beneath of a peculiar glaucous greenish white, with a 

 median reddish line. Thoracic and abdominal legs dull livid reddish. Length 20"'"'. 

 Observed not unfrequently at Brunswick, Me., late in August; also found feeding at 

 Brunswick on the low-bush common juniper (Juniperus communis) August 26-29, 1881. 



Moth. — Difi"ers from Eiipithecia miserulata in the much longer, more pointed fore 

 wings. The palpi are also larger, acute, and black. It has four regularly curved 

 parallel black lines on both wings ; it is also characterized by the broad, clear, flesh- 

 yellow or luteous band situated between the discal dot and the extradiscal line. 

 Expanse of wings, 22™">. 



16. The angular-headed, marbled fir inch-worm. 



Order Lepidoptera; family Phal.enid.c 



(Plate X, fig."2.) 



Feeding on the leaves in Maine, late in August, also on cedar, August 30, 1883, a 

 very slender inch-worm ; the body tuberculated, blackish brown. Head angular ; 

 the vertex angulated above on each side. Body with five pairs of well marked small 

 prominent lateral tubercles ; sutures between the segments not well marked, so that it 

 is difficult to tell on which segment the tubercles are situated. Body wood-colored, it 

 is the shade of the bark of the tree, mottled with black-brown, reddish gray and gray 

 markings. Head marbled or mottled like the body, with a whitish line along the 

 top of each side, and continued along the prothoracic segment, and in the form of two 

 broken white faint lines along the sides towards the end of the body. Anal legs 

 much larger than the other abdominal legs. Length about 20""". 



This caterpillar is not specially mimetic, though it is probably pro- 

 tected from the search of birds by its general resemblance to a dry fir 

 twig. It may be recognized by its angular head, dark marbled body, 

 colored like the bark of the branches on which it rests, and by the five 

 pair of sharp, prominent small tubercles. It closely resembles in color- 

 ation the caterpillar, Olygia versicolor. Plate xxxiii, figs. 1, la-lli, also 

 represent the caterpillar. 



17. The ten-lined pine span-worm. 



Feeding on the leaves of the fir, hemlock, and spruce, an inch- worm with a very slen- 

 der body, with minute prominent tubercles, and a large, full, rounded head ; the latter 

 deeply divided in the middle, and much wider than the body. The general color a 



