The first part of the present work aims to provide two main goals: to generalize the basic results of investigations of previous works and to give some author's ideas on the philogeny and systematics of terrestrial molluscs of the order Neritopsiformes. The author has examined as many type species of the genera (subgenera) as possible; moreover illustrations and/or descriptions from original or later publications were studied. In total, type species (or, at least, similar to type species) of 70 recent taxa of genus group are described and illustrated in the book; the figures of more than 70 shells are original. The description, illustration and discussion of one subfossil pulmonate genus Pseudotrochatella Nevill, 1881 are given. As concerns anatomical drawings (radula and/or reproductive system), there are over 80 figures; all of these are taken from previous works. For most taxa descriptions and illustrations of operculums are given. Synonymy and systematic position of some taxa were revised. Key for identification of the families, genera and some subgenera of the suborder Helicinoidei based on conchological characters is given. The key include pulmonate genus Pseudotrochatella which early was referred to the Helicinidae. Appendix 1 contains the descriptions and illustrations of four fossil genera of the family Proserpinellidae. Appendix 2 contains the discussion and data on recently described genus Microalcadia Richling, 2004 stat. nov. The list of cited literature contains 157 references.