A Manual of Conchology / According to the System Laid Down by Lamarck, with the Late Improvements by De Blainville. Exemplified and Arranged for the Use of Students.

by Thomas Wyatt

P. vortex.

P. deformis.

P. contortus.

P. hispidus.

P. nitidus.

P. imbricatus.

P. carinatus. The keeled Planorbis.

Species with a keel; depressed, upper side concave.

P. corneus. The horny Planorbis. Pl. [20], fig. 4.

Species without a keel.