2(36 MEMOlliS OF TOE NATIONAL ACADEMY OF SCIENCES. 



"The cocoon is a rather close, line silken one, and transparent when the outer protecting 

 material is removed. This last may be either a leaf, folded or otherwise, excrement, or other 

 matter which the larva entangles in the loose outer web of the cocoon for concealment and 

 protection." (Kiley MS.) 



Pupn. — Like that of S. Ipomcw, but sliglitly shorter, and the spine of the cremaster a little 

 more acute. Hinder edge of thorax, witli a transverse series of nine square black tubercles; 

 surface slightly punctured, especially on the front edge of abdominal segments 5-7, the last three 

 segments smooth, tip rather blunt. Cremaster small, the two spines short and stout, granulated 

 and corrugated on the surface. Length, 20 mm. (From U. S. Nat. Mus.) 



This is our commonest Schizura, and occurs on the willow and thorn late in August in Elaine. 

 August 28 one liad spun a slight <-ocoon. 



"Length varying from 12 to 21 mm.; color rich shiny brown. In general characters, and 

 especially in the row of eight blunt, tooth-like, dull, black projections from the jiosterior dorsal 

 margin of the niesothorax, it resembles closely the pup;e of the two other species of this genus 

 which have this stage described, viz, *S'. leptinoides and S. ipomeiv. From these species it may be 

 distinguished, however, by the character of the two prongs to the cremaster. These are much 

 shorter than those of ipomew (which are three times as long as wide), being scarcely longer than 

 the width, and the inner branches or teeth are short, and the small inner basal teeth are absent 

 or nearly so. 8. leptinoides is readily separated by the fact that the branches in this species are 

 themselves branched or bitoothed. 



"About four days are required for jjupation from the spinning up of the larva. At tirst the 

 color markings of the larva are retained with considerable distinctness in the pupa, but these are 



soon lost and the normal brown color assumed." (liiley MS.) 

 I ^"""'^^ ^""^'^^ ; Iluhitn. — The caterpillar of this moth, more commonly met 



\/^ Ay"'"? with on the apple tree, we have found September (J on the elm at 



^ . I Brunswick, Me. At about this date, Harris says, it makes its 



\ j/ ^\^ jS) cocoon, which is thin and almost transparent, resembling parch- 



\y^ ^^"t ment in texture, and covered generally with bits of leaves on the 



( ^ V / outside. The caterpillars remain iu their cocoons a long time pre- 



\ /^ >, / ^ vious to changing to chrysalids, and tlie moth appears tlie follow- 



\ '(®J J ^^^ ^biy and June. 



^X^IT' /\n '^\\\^ and the other species of the genus aredoubtless protected 



\>\l from the attacks of birds by their close resemblance to a dead, 



^. _„ „ „ ,. , . . . dry portion or blotch on the edge of the leaf, as they usually feed 



J?ig. 79.— Pupa of Ac/d^Mrft tt/uconM^. ^ ^ ^ ^ i ^ ^ 



on the edge. 

 Miss Emma Payne was the tirst to call attention to its mimicry of leaves partly tlead. We 

 quote her interesting account: 



I think this worm furnishes a wonderful Instance of mimicry of the vegetable by the animal organism. The 

 green segments just back of the head resemble a small portion of the green leaf, and the other parts admirably 

 counterfeit the brown and russet tints of the dead leaf, while the form of the animal in its various postures aids the 

 deception by its resemblance to a leaf partly alive and partly dead, the green mostly eaten and thebrowu torn. 

 (Amer. Eut., ii, p. 341.) 



I have noticed that this caterpillar feeds very conspicuously, but is protected by its resemblance 

 to the twisted, partly dead ends of some of the leaves, the oblique markings of the larva resembling 

 the twisted dead and russet ijcntions of the leaf. 



The following observations have been made by Professor lliley: 



"The larva of the above species is found feeding on quite a number of different plants, such as 

 oak, elm, plum, apple, dogwood, alder, winterberry, rose, and blackberry, also on hickory. 



"The insect is evidently two brooded, those of the first brood spinning up at the coinmence- 

 ment of July, while larvie of a second brood, often only about one-fourth grown, are found as late 

 as October 10. 



"The cocoon is very thin and looks much like parchment. It frequently draws a few leaves 

 together for this purpose, and changes to a chrysalis in about four days, whicli is at first of the 

 same color as was the caterpillar, the green segments being distinctly visible, but soon changes to 



