♂ . A small frail form with ciliate antennae no ocelli, and long, dependent palpi, their second joint thickly squamous. Fore wings grayish white, with their inner line black, fine, angulated. Outer line denticulate, followed by a pure white shade. A pure white shade in the place of the subterminal. Hind wings dusty white. Beneath the fore wings are pale fuscous, immaculate; hind wings whitish with a discal dot. Expanse 16 m.m. Canada, Mr. Saunders. This species differs decidely from the N. Am. species described by prof. Zeller; I do not find descriptions of N. Am. species in any other author.

Dr. Weismann has lately published an account of certain experiments made by him during a course of years with a view to determining the facts relating to seasonal-dimorphism, and from them to deduce the reasons for the phenomena. As several North American butterflies are thus dimorphic. I have thought that the substance of Dr. Weismann's paper would be interesting to the readers of the Entomologist, it being too long to print in full.

Those of the members who accepted Mr. Jack's kind invitation to visit him on Dominion Day, left town on Thursday, the 30th June, by the 5 p. m. train, for Lachine, where they took the boat and had a delightful sail up the Chateauguay River as far as the Basin, where they were met by Mr. Jack, who conducted them to his beautiful residence, where they were warmly welcomed by the rest of his family.