CRASPEDOPOMA. 13 



6. Pterocyceos BIEABIATUS. 



Cyclostoma bilabiatum Sow. Thes. Conch. 1. 110. n. 57. t. 25. 



f. 81—82. 

 Pterocyclos bilabiatus Benson (in Sow.) ; Pfeiffer, Kuster, Chemn. 



Conch. Cab. i. 19. t. 24. f. 11—14.; Pfeiffer, I.e. 111. n. 1. 



Hab. Salem near Madras. 

 Near Cyclotus planorbulus. 



3. CRASPEDOPOMA. 



Operculum horny, solid ; whorls very narrow, with a central nucleus ; 

 external plate flat ; internal concave, furnished with a circular 

 marginal prominence. — Shell subturbinate, gaping; last whorl 

 slightly produced, straight. Mouth circular, rather contracted. 

 Peristome continuous, simple, receiving the external prominence 

 of the operculum. Axis imperforate. 



Craspedopoma Pfeiffer in Menke und Pfeiffer, Z.f. Malak. 1847, 



48. 107. 

 Cyclostoma sp. Lowe. 

 Valvata sp. Menke. 

 Bolania Gray, Syn. B. M. 1842, 91., not described. 



§ Last whorl slightly produced. 



1. CRASPEDOrOMA EUCIDEM. 



Cyclostoma lucidum Lowe, Moll, of Madeira, Trans. Carnb. Phil. 



Soc. 1831, 66. t. 6. f. 40. ; Lamck. An. s. Vert. 2d ed. viii. 369. 



n. 36. ; Pfeiffer, Kuster, Chemn. Conch. Cab. i. 19. t. 13. 



f. 26, 27. 

 Valvata turbinata Menke ? 

 Craspedopoma lucidum Pfeiffer, 1. c. 111. n. 1. 

 Bolania lucida Gray, B. M. 1840. 



a—f. Madeira. Presented by Rev. R. T. Lowe. 

 g — t. Madeira. Presented by T. V. Wollaston, Esq. 

 u — z. Madeira. Fossil. Recent limestone formation. Pre- 

 sented by T. V. Wollaston, Esq. 



§§ Last whorl much produced, straight. 



2. Craspedopoma Lyonnetianum. 

 Cyclostoma Lyonnetianum Lowe MS. fide Wollaston. 



a — r. Madeira, wet rocks. Presented by T. V. Wollastou, 

 Esq. 



s — x. Madeira. Fossil. Recent limestone formation. Pre- 

 sented by T. V. Wollaston, Esq. 



