The preceding part under this general title was published in 1921 (Can. Ent. 53 : 132-137). The species discussed at this time are all included in the very extensive series of these flies belonging to the Canadian National Collection and kindly sent to me for determination by Mr. Curran. I am greatly indebted to Mr. Curran, and to the various collectors of the material, for the opportunity of studying this important series of specimens.