ENTOMOLOGICAL CONTRIBUTIONS. 143 



the remaining portion of the cocoon. With the same economy of 

 labor and of material shown in the construction of the inter- 

 rupted "packing," these laminae do not encircle the cocoon, but 

 disappear beneath the hinge. 



The separate construction of the lid, as shown in the remarkable 

 evidences of design above recorded, is also confirmed by microscopic 

 observation. Under a high magnifying power, the parallelism of 

 the threads composing its margin is distinctly seen, in marked con- 

 trast with the ragged projecting ends of an excised portion. 



Pupation. The larvae made their cocoons between the leaves on 

 which they had fed, or those lying on the surface beneath. In 

 several instances, a half dozen or more were found associated between 

 a couple of leaves, and so firmly attached to one another that they 

 could with difficulty be separated. Of perhaps eighty cocoons 

 obtained, eight only developed the moth during the last of October 

 and early part of November, after a pupation of about two months. 

 None were disclosed in the spring, at the regular time for its apparition 

 during the month of June, as we may infer from the collection of its 

 eggs on the full grown leaves of oak. In a number of the cocoons sub- 

 sequently opened for examination, were found the shrunken remains 

 of untransformed larvae, and in others, the apparently fully matured 

 pupa, seen through the thin case, perfect in all but the extension of 

 its wings. 



It is worthy of remark that this species, Hyperchiria lo and 

 Hemileuca Maia have each, in my experiments in rearing them, 

 produced a portion of their brood in the early fall, at a time when 

 their exclusion could not be the result of an indoor temperature, 

 which at that period did not exceed that of their natural exposure. 



When in readiness for its final metamorphosis, the pupa forces 

 upward the lid of the cocoon, and withdraws itself through the open- 

 ing, until only its terminal segments are held by the pressure of the 

 lid and enveloping convergent threads. As the pupa is wholly 

 destitute of the dentiform processes which encircle the pupal segments 

 of those of our moths (^Egeriadse, Cossidae et al.), which are known 

 to extrude themselves partially from their cocoons while still in their 

 pupal state, and which apparently are dependent on aid afforded by 

 these processes for their release, some other provision is required by 

 crispata to serve in its work of extrication. This is found in the 

 motion permitted its encased limbs while yet a pupa. As a general 



