monograph of the little slit shells

Two volumes box set that examines 9800 lots and 73000 specimens. The group comprises basal marine snails (Vetigastropoda), which are minute, usually have a slit or foramen and lack nacre. The monograph treats all taxa ever described as scissurellids, recent and fossils. All original illustrations are reproduced, comprehensive synonymy and literature listings are provided, multiple specimens per species are illustrated; radula, external anatomy and distribution maps are provided.