The preceding part under this general title was published in 1941 (Can. Ent., 73:85-90). The majority of the novelties discussed herewith were collected by myself in the mountains of Colorado; for other specimens I am indebted to Professor Harry C. Severin, South Dakota State College; Dr. Charles D. Michener, University of California; and Dr. Alan Stone of the United States National Museum. Where not indicated to the contrary the types of the novelties are preserved in my extensive collection of these flies.