Ferris, G.F. 1957b Notes on some little known genera of the Coccoidea (Homoptera).. Microentomology 22: 59-79.

Notes: Brief descriptions with illustrations and discussions of genera: Apiomorpha (6 species), Ascelis (type), Cylindrococcus (spiniferus), Aculeococcus (type), Macracanthopyga (type), Opisthoscelis (species), Calycicoccus (type), Micrococcus (type); diagram of author's concept of major group associations in Coccoidea.