The Entomological Society of Ontario has been kindly remembered by Messrs. J. and H. Comstock, Evanston, Ill., in a contribution to its collection of a number of butterflies taken by themselves in a trip through Colorado during the season of 1902. Carefully done up in papers, named and dated, with the localities in which they were taken, these specimens are of special interest as representing much-discussed forms of that famous locality, which hitherto have been known to us only by name.