POPLAR CATERPILLARS. 453 
indistinct towards the second, which gives to the sides the appearance of a broad, 
dusky stripe marked with three black lines.* The thinly scattered hairs on the body 
are whitish, and proceed indiscriminately from the surface, and not from regular 
tubercles. 
The cocoon spun at Providence about the middle of September, is a 
loose web with abundant brown strands made in a folded leaf. 
Larva. — Body as wide on the third thoracic segment as on the eighth abdominal. 
Head as wide as first and second thoracic segments; flattened in front, uniformly- 
deep black. First thoracic segment short and small, with two sublunate black shin- 
ing spots. On the first abdominal segment are two black rounded fleshy conical 
tubercles, surrounded at the base with short black hairs, and bearing at the end a 
white hair. A similar double tubercle on the eighth segment, the latter pair (in life) 
nodding over backwards at regular intervals independently of the surrounding skin 
(a very singular phenomenon ; the anterior pair does not move), Along the back are 
four yellow stripes inclosing three black somewhat interrupted lines. On the sides- 
are three broader black bands and a supra-spiracular yellow line. A broad yellow 
ocherous lateral band inclosing the black spiracles. Thoracic feet black ; abdominal 
feet mostly reddish brown, black near the ends. Body with numerous white hairs 
arising from small warts. Length, 30 mm . 
Pupa. — Large and thick; wings not reaching to the hinder edge of the third 
abdominal segment ; abdomen full and rounded at the end ; the terminal spine (cre- 
master) forming a slender rouuded spine scarcely thicker at the end than at the base, 
and terminating in two forks which are suddenly twisted back or recurved, and 
ending each in three minute acute spines. Length, 17 to 18 mm . 
23. Ichthyura strigosa Grote. 
The caterpillar of this interesting species was found July 30, at Bruns- 
wick, Me., feeding on the aspen (Populus tremuloides). It molted 
August 10, and about the 20th began to spin a silken cocoon between 
two leaves. The moth (a male) appeared in the breeding cage at Prov- 
idence, May 20. Like J. inclusa, it sits with the wings folded sharply 
over the back, with the fore-legs held straight out in front, with the 
tufted tail upcurved. 
Larva before the last molt. — Head broader than the body, flattened in front, dull 
black, with long white hairs. Body flattened, with yellow and reddish longitudinal 
stripes ; three dorsal faint red stripes on a yellowish ground, and three deep lake-red 
lateral stripes, the lowermost the broadest and deepest in hue. Two bright ^yellow 
lateral stripes. Five pairs of flesh-colored abdominal legs, the legs pale amber, 
colored like the under side of the body. Length, 9 mm . 
Larva after the last molt. — Markings much as in the previous stage. Length, 17 to 
18 mm . 
The rude cocoon is formed by tying a few leaves together, gathering them by a web 
at the edges, thus forming a roomy chamber, partly lined with silk, within which the 
chrysalis rests. 
Pupa. — Smaller and not so full and rounded at the end as in I. inclusa ; cremaster 
as in that species, ending in two stout, very short, recurved spines. Length, 12 mra . 
Moth. — One male. Smaller and duller brown than 1. indentata Pack. Palpi whit- 
ish below, dark brown above, as in /. indentata (which closely resembles Fitch's I. 
* The middle lateral line is very slender, the lower one broader, more distinct than 
the upper one ; and below it, between and below the spiracles, are irregular, 
blackish spots which sometimes run together so as to resemble a fourth line. The 
tubercles have hairs as well as the body. (Harris Corr.) 
