Contents. 



I. Introduction. 



II. Methods. 



III. Natural History of the "Shipworms". 



IV. Organization and Late Development of the "Ship-wontis". 



a. The Organization and Metamorphosis of the Larva 



b. The General Organization of the Adult. 



c. The Shell and the Palettes. 



d. The Kantle and the Siphons. 



e. The Muscular System. 



f. The Respiratory System. 



g. The Circulatory System, 

 h. The Alimentary Canal. 

 i. The Neiwous System. 



j . Tlie Kidneys. 



k. The Reproductive Organs. 



1. Conclusions. 



V. Bibliography. 



VI. Explanation of Figures. 



