Seeing in the last number of the Canadian Entomologist, a description of the egss of A. Luna, reminds me to ask of you the explanation of a curious circumstance in the life-history of one bred by me from the larva last year. I will premise that I am writing without my notes, and therefore cannot give figures accurately, but can give the facts. There may be nothing very strange about it, but two of the best entomologists in the United States inform me that it is entirely new to them. It is this:–Some time in the latter part of the summer of 1868 I took, feeding on walnut leaves, a mature larva of A. Luna; from which I did not houi to rear the mature insect, because I counted on the larva over twenty eggs like those of a Tachina, Underneath some of the eggs I could discern with a lens a minute opening through which the fly-larva had entered the body of the Luna larva. The skin of the latter was more or less discoloured under each egg, but under some-under many in fact there was a dense black spot, sometimes two lines in diameter.