This paper includes illustrations, descriptions, and keys to the following eight genera and 42 species: Atheroides serrulatus Haliday, Caricosipha paniculatae BÖrner, Chaetosiphella berlesei (del Guercio), Chaitophorus abditus (Hottes), Chaitophorus albicentrus new species, Chaitophorus canens Richards, Chaitophorus crucis (Essig), Chaitophorus delicatus Patch, Chaitophorus longipes Tissot, Chaitophorus knowltoni Hille Ris Lambers, Chaitophorus macgillivrayae new species, Chaitophorus macrostachyae (Essig), Chaitophorus minutus (Tissot), Chaitophorus monelli (Essig), Chaitophorus neglectus Hottes and Frison, Chaitophorus nigrae Oestlund, Chaitophorus nigricentrus new species, Chaitophorus nodulosus Richards, Chaitophorus nudus Richards, Chaitophorus pallipes new species, Chaitophorus populialbae (Boyer de Fonscolombe), Chaitophorus populicola Thomas, Chaitophorus populifolii (Essig), Chaitophorus pusillus Hottes and Frison, Chaitophorus pustulatus Hille Ris Lambers, Chaitophorus saliciniger (Knowlton), Chaitophorus versicolor (Koch), Chaitophorus viminalis Monell, Chaitophorus viminicola Hille Ris Lambers, Laingia psammae Theobald, Periphyllus americanus (Baker), Periphyllus brevispinosus Gillette and Palmer, Periphyllus californiensis (Shinji), Periphyllus lyropictus (Kessler), Periphyllus negundinis (Thomas), Periphyllus testudinacea (Fernie), Pseudopterocomma canadensis Richards, Pseudopterocomma hughi (MacGillivray), Sipha agropyrensis (Gillette), Sipha flava (Forbes), Sipha glyceriae (Kaltenbach), Sipha kurdjumovi Mordwilko. A host index has been compiled from the material studied and the literature cited.
