I have received form Mr. Behrens, of San Francisco, the following descriptions for publication, and with them the specimens to which they refer. The Papilio is a very extraordinary aberration, probably owing its color to a change in the food plant. I learn from Mr. Behrens that four specimens were obtained, all agreeing with each other. The Catocala is, I have no doubt, the form referred to by me (Pacific Coast Lepid., No.14, Proc. Cal. Acad Sc., 1875) as having been seen by the late Baron Terloo at San Jose, Cal. I think it a good species, and in this view I am sustained by those excellent authorities on Catocala, the Rev. G.D. Hulst and Prof. G.H. French.