The present work is continuation of the "Review …" series, which started in 2005. The fourth part of the series is dedicated to review of the genera of one of most diverse group of pectinibranchs of the order Rissooiformes. Terrestrial representatives of this order belong to five families: Assimineidae, Truncatellidae, Pomatiopsidae, Tateidae, Terrestribythinellidae. The modern systematics and nomenclature of these groups are reviewed and clarified. For each taxon the original reference, synonyms, descriptions, as well as habitat and distribution are given. Also, representatives of the order Littoriniformes with unclear systematic position are added in separate chapter. The systematic position of the genus Dominamaria Iredale, 1941 is still unclear and discussed here. The images of type species of the genera Ettemona Iredale, 1941 (holotype of E. perspicua Iredale, 1941) and Dominamaria (Memonella) Iredale, 1941 (two syntypes of Dominamaria addita Iredale, 1941) are published for the first time. Images of types of the type species of the assimineid genera Eussoia and Pseudassiminea are published for the first time too.
In total, the present work contains descriptions and illustrations of 63 genera and subgenera, mainly of the type species or their close relatives. Some illustrations are original but most are taken from previously published works. The list of cited references contains 201 titles. The Appendix contains the list of all genera of the family Assimineidae with illustrations of all type species.