The 4th vol. was issued as a separate work. ("At one time it was intended to add to the present volume the terrestrial operculate genera ..."--Introd.).
Includes bibliographical references and indexes.
v. [1]. Testacellidæ and Zonitidæ / by W.T. Blanford and H.H. Godwin-Austen. 1908 -- v. 2. Trochomorphidæ-Janellidæ / by G.K. Gude. 1914 -- v. 3. Land operculates (Cyclophoridæ, Truncatellidæ, Assimineidæ, Helicinidæ) / by G.K Gude. 1921 -- v. [4]. Freshwater Gastropoda & Pelecypoda / by H.B. Preston. 1915