Eenige biologische gegevens over een aantal soorten Clausiliidae

Some species of the Clausiliidae have been kept in glassboxes with the intention to obtain data about their propagation, offspring, etc. The main results of a five years breeding are given. As already known Laciniaria biplicata (Mont.) and Clausilia (Iphigena) ventricosa Drap. are ovoviviparous, although it turned out, that they too are able to lay eggs. Eggs are placed by the snails under or in crevices of a little piece of bark, which was put in each of the containers, and were nearly always found in heaps of two till twelve, exceptionally fifteen. Mostly incubation took some weeks. Most of the species investigated growed to maturity in about a year, only Clausilia (Iphigena) plicatula Drap. and Fusulus varians (C. Pfr.) required less time.