CONCHOLOGY. Ill 



P. mumia. The double-toothed Pupa. PI. 19, fig. 2. 

 Species cylindrical, obtuse at both ends, aperture semi- 

 ovate, with two teeth, 



6. Clausilia. Twelve species. 



Remarkable for having the termination of the lower whorl 

 quite detached from the base of the shell. 



Shell cylindrical, elongated, a little ventricose in the mid- 

 dle, generally fusiform, summit obtuse, the last turn smaller 

 than the preceding; aperture small, irregular, oval; at least 

 one plait, posterior to the columella, increasing with age so 

 as to be separated, and forming at the posterior angle of the 

 aperture a rounded sinus. 



Clausilia torticollis. Clausilia teres. 



C. truncatula. C. denticulata. 



C. retusa. C. collaris. 



C. costulata. C. papillaris. 



C. corrugata. C. plicatula. 



C. inflata. C. rugosa. 



C. IcBvis. The smooth Clausilia. PI. 19, fig. 3. 

 A regular type of this genus. 



C. papillaris. The pimpled Clausilia. 



Pellucid, finely striped longitudinally, the margins of the 

 volutions papillose ; aperture with two plaits ; brownish col- 

 our. 



7. Bulimus. Thirty-four species. 



The shells of this beautiful genus are all terrestrial, and 

 differ from the Helix and Bulla of Linnaeus in never being 

 of an orbicular shape. The animals inhabiting them are 

 said to be oviparous, and have eggs nearly as large as those 

 of a pigeon. 



Shell oval, oblong, sometimes sub-turriculated ; the sum- 

 mit of the spire obtuse, and the last turn much greater than 

 all the othet-s taken together ; aperture oblong oval, the edge 

 disunited ; the right reflected outward in adults ; the colu- 



