Plate VIII. 



Vol. IV. 



Helix arbustoriim. — i, Dart-sac and simple mucous glands x 2. 2, Another 

 example with bifid gland, nat. size. 3, Dart. 4, Dart not quite mature. 



Helix lapicida. — 5, Dart-sac and mucous glands, nat. size. 6, Another 

 example enlarged. 7j Dart. 



Helix piilchella. — 8, Dart-sac, etc., x 35. 9, Dart, x 100. 



Helix aspersa. — 10, Dart-sac and multifid glands, nat. size. 11, Single 

 gland with few branches. 12, Single gland unusually ramose. 13, Dart. 

 14, A malformed dart. 15, An abnormal dart. 16, Base of a dart approach- 

 ing completion, much enlarged. 17, Young darts in three stages, x 3. 18, 

 Base of mature dart, much enlarged. 



