POLYGYRA ALBOLABRIS AND LIMAX MAXIMUS 295 



EXPLANATION OF PLATES 

 Polygyra albolabris 



PLATE 1 

 Fig. — 



1-3 Dorsal, profile and ventral views of an adult shell, natural 



size. 

 ,4 A profile view, showing a more flattened form than in 



fig. 2. 

 5, 6 Ventral and profile views of a young shell, the peristome 



being as yet unformed. 



7 Ventral view of an adult shell, showing the form of the 



under side of the peristome. 



8 Profile view of a shell just after leaving the egg, x 10, the 



perpendicular line to the left of the figure showing the 

 natural size. Figures 9, 10 and 11 are also enlarged, the 

 perpendicular lines to the left of the figure showing the 

 natural size as in fig. 8. 



9-11 Showing succeeding stages of the form of the shell before 

 reaching maturity. 



12 An adult shell. 



13 In this figure a part of the lower volution of the shell is 



broken away to show the interior. 



14 A section of a shell. The outer part of the shell is ground 



away in order to show the columella. 



15 A section. The columella has been ground down to show 



its interior. 



PLATE 2 



Fig. 



1 An egg natural size and enlarged. 



2 A view showing the shell within the egg. 



3 A view showing the shell emerging from the egg. 



4 Dorsal and profile views of a shell, newly hatched, natural 



size and enlarged. 



