VII 



MOLL USGA — ,S YHTEMA TIG RKVIE U ' 



/^ A 



Fig. 12.—^, Hellz pomatla ; B, Daudebardla (Helioophanta) lirevlpes ; C, Testaoella hallo- 

 tidea; D, Arion ater ; s% shell, in D sliield (from Lankester). 



Fig. is.— Peltella palllolum(Bu?i»n(;i(/, after Ferussao). 



