It may be necessary o state that the names which I have used for the different nervures of the wings in thesc papers are those used by Dr. Clemens, and differ somewhat from those in use by European entomologists.

Various means may be used for the purpose of denuding the wings of their scales, so as to render the neuration distinct. The wing may be process repeated slightly between two pieces of moinstened bibulous paper, and the process repeated until the wing is sufficiently denuded ; or, if this does not denude it sufficiently, the fewremaining scales may be removed with a camel's or sable hair brush.

In their papers on various species of British Macro-Lepidoptera, Messrs. Hellins and Buckler furnish us with much better accounts of the external appearance of caterpillars than can be gained from the meagre and superficial descriptions which used to be thought sufficient; and, as they have not confined their descriptions to the full grown animals, but have followed the creatures through all their moults, they have, in several cases, incidentally shown how great a difference there is between the larva just hatched and the full grown caterpillar; especially in the case of some of the Rhopalocera thus treated by them. Mr. Riley, of America, has, in one or instances, recorded similar facts.

This insect in the imago state closely resembles A psi of Europe, and has been, ans we believe still is, doubtfully regarded as identical by several eminent European entomologists. We thinks, however that a comparison of the larval forms of the two insects will help to dispel any doubts which may be entertained regarding the dissimilarity of the species. The following descriprion of the larva of occidentalis has already appeared in part, in the Annual Report of the Entomological Society of Ontario to the Commissioner of Agriculture for 1870, where it is given.