PLATE 112. 



Page 



Fig. 1 - 10. Platyostoma ventricosa. 469 



1 & 2. Young shells of this species. 



3. A young specimen, showing a broadly undulating surface. 

 4 a. View of the aperture of the same. 



4 b. An older specimen of the ordinary form. 



5 a, 6. View of the spire, and of the aperture of a specimen of medium size. 



5 c. Profile of a specimen which is somewhat depressed vertically. 



6. A young specimen with a more elevated spire. This is of the type of P. arenosa of Conrad 

 ( See Plate lvii). 



7 & 8. View of the spires of two specimens of ordinary form. 



9. A specimen which has been vertically compressed. 



10 o, b. View of a specimen which is a little compressed obliquely. 



