EXPLANATION TO PLATK I. 



Fiy. 

 la-lc. Helix foiluiiilis, Talh. Three \-iew,s slightly enlarged. 



2a-2c. Helix Elderi, Bednall. Three views slightly enlarged. 



3a-3c. Helix Everardensis, Bednall. 'J'hree views slightly eidarged. 



4. Jaw of Helix Klderi, niagnifie<l. 



5. Six tectli from different regions of the radula of Helix Elderi ; 



their relative positions are indicated bj- uuiiierals annexed. 

 Highly magnified. 



6. Helix x)erinflatii, Pfeiffe.r. Kat. size. 



