LIST OF ILLUSTRATIONS xi 



PLATE 



XXVII. Feeding Tracks of Snail and Slug. 



XXVIII. Life-History of the Coral-Inhabiting Magilus. 



Example of a Fibrous Form of Outer Covering, 



or Periostracum, and of a Mollusc (Xeno- 



phora) that Builds into its Shell Fragments 



of other Shells, Corals, and Stones. 



XXIX. Typical Molluscan Embryos. 



Diagrammatic Sketches of the Structure of 

 Molluscan Eyes, etc. 



XXX. Eggs and Egg-Capsules, etc., of Some Gastropods. 

 Sections of Some Thick Bivalve Shells. 

 Variations of the Foot in Bivalve Mollusca. 



XXXI. Common Garden Snail Crawling, and showing 

 the Motion of the Foot. 



XXXII. Eccentric Forms of Gastropod Shells, and 

 Examples of the External Resemblance 

 between Shells of Widely Different Forms 

 of Mollusca. 



Map. 



All the Plates (except Plate I ., frontispiece) and the Map are at the 

 end of the booh. 



