At the suggestion of Professor G.F. Ferris, of the Department of Entomology of Stanford University, I have undertaken the following review of this extremely important, equally interesting, and almost equally neglected group of the Coccidae. My acknowledgements are due to Professor Ferris for his aid in the preparation of the paper and of the material upon which it is based. To my fellow-students, Mr. Bryan Duncan, Mr. Carl Duncan, Mr. W.H. Irwin and Mr. P. N. Annand, I desire to extend my thanks for their aid in testing the included keys.