I am very much indebted to Mr. T.N. Willing, a Regina, Assa., for the privilege of working up a very interesting collection of Micro-Lepidoptera. It is particularly notable in recording a number of species that have hitherto been only known by the types, and especially so in establishing a wide range of territory to species that have been only recorded from California. Following this paper I have one in preparation on the same subject, from material collected in Manitoba by Messrs.