POPLAR CATERPILLARS. 453 



indistinct towards the second, which gives to the sides tho 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 span 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™"". 



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""". 



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, Q"""". 



Larva after the last molt. — Markings much as in the previous stage. Length, 17 to 

 18""°. 



The rude cocoon is formed by tying a few leaves together, gathering them by a web 

 at the edges, thusformmg 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. Lengtli, 12""™. 



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 /. 



* 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. ) 



