Notes on Kenya land- and freshwater snails

This species is perhaps the commonest snail in the forests surrounding Nairobi, being particularly common in the Karura Forest and the Chania Falls gorge. Both these localities are very similar botanically with Piptadenia buchananii, Uvariodendron sp. nov., Rawsonia usambarensis, Teclea, Drypetes and Strychnos being dominant. Although the shells are so common, I have only found living specimens on rare occasions. The body is opalescent, the foot being colourless, and the back very pale brick red. Under a lens it is seen that actually only the tops of the dorsal corrugations are coloured, the grooves being pale. A white epighragm is formed. The radula of a young ¼ grown specimen was mounted and some representative teeth are figured (fig. 1). The radula is 0,8 mm broad and 1,7 mm long. There are 68 rows of teeth, ten of which stain in acid dyes. The central tooth is small, 10 µ broad, with an emarginate base. There are 8 laterals having a large mesocone, small ectocone and no true entocone. The mergence into the marginals is gradual. There are about 15 marginals. My thanks are due to Dr. BEQUAERT for naming material sent to Harvard. This snail is easily recognised by the extremely strong spiral grooves on the apical whorls.