Fam. 6. Orthalicidae.—Radula, p. [233]. Shell external, large, bulimoid. Single genus, Orthalicus; subg. Liguus, Porphyrobaphe, Corona.
Fam. 7. Bulimulidae.—Radula, p. [233]; jaw, p. 211; shell usually external. Genera: Bulimulus (incl. Plecochilus, Goniostomus, Drymaeus, Liostracus, Otostomus, Navicula, Scutalus, Peronaeus, Eurytus, Eudioptus, Plectostylus, Mesembrinus, Mormus, etc.; Thaumastus, Nesiotis), Placostylus (incl. Charis), Amphidromus, Partula, Calycia (?), Peltella (animal limaciform, shell internal), Pellicula, Amphibulimus (incl. Simpulopsis).
Fam. 8. Cylindrellidae.—Radula, p. [233]; shell many whorled, long turriculate, last whorl often detached, apex often truncated (Fig. [169], p. 260). Eocene——. Genera: Cylindrella (with sections Callonia, Thaumasia), Leia, Macroceramus, Pineria.
Fam. 9. Pupidae.—Radula, p. [233]; shell external, spire usually long, aperture often narrowed, more or less toothed, often with internal lamellae. Carboniferous——. Genera: Anostoma (Fig. [154], p. 248), Hypselostoma (Fig. [202]A, p. 302); Anastomopsis (Cretaceous), Lychnus (Cretaceous), Boysia, Odontostomus (incl. Tomigerus), Buliminus (incl. Petraeus, Napaeus, Zebrina, Mastus, Chondrula, Ena, and perhaps Rachis, Pachnodus, Hapalus, and others), Pupa (incl. Torquilla, Pupilla, Sphyradium, Leucochila, etc.), Zospeum, Vertigo, Megaspira, Strophia, Holospira, Eucalodium (incl. Coelocentrum), Coeliaxis, Perrieria, Balea; Rillya (Eocene), Clausilia (with many sub-genera), Rhodina (?).
Fig. 297.—A, Clausilia crassicosta Ben., Sicily; B, Clausilia macarana Zieg., Dalmatia; B´, clausilium of same.
Fam. 10. Stenogyridae.—Radula, p.[ 234]; shell long, spiral, shining, more or less translucid, apex blunt, sometimes decollated. Eocene——. Genera: Stenogyra (subg. Rumina, Obeliscus, Opeas, Melaniella, Spiraxis, Leptinaria, Nothus, Subulina, Glessula), Ferussacia (subg. Cionella, Azeca), Caecilianella (subg. Geostilbia). Achatina (shell large, ventricose, columella strongly truncate), with the sub-genera Perideris, Limicolaria, Columna, Pseudachatina, Homorus, probably belongs to a distinct family.
Fam. 11. Achatinellidae.—Radula, p. [234]; shell small, bulimoid, indifferently dextral or sinistral. Genera: Achatinella (subg. Auriculella, Amastra, Carelia), Tornatellina.
Fam. 12. Succineidae.—Radula, p. [234]; lower pair of tentacles wanting or small; shell internal or external, thin, spiral or not, last whorl large. Eocene——. Genera: Succinea, Homalonyx, Hyalimax, (?) Lithotis, (?) Catinella.
Fam. 13. Janellidae.—Radula, p. [234]; animal slug-like, no lower tentacles, shell an internal plate. Single genus, Janella (= Athoracophorus), with subg. Aneitea.