32 THE AMERICAN MUSEUM JOURNAL 



THE SLIPPER LIMPET OR BOAT SHELL 



Crepidiila jornicata Lamarck 



The Development of Crepidula. 



The models represent on a greatly enlarged scale (about 400 

 diameters) the more important stages in the development of the 

 egg of a gasteropod mollusk of the genus Crepidula — the Slipper 

 Limpet, or Boat Shell — common on the coast of the United 

 States. The exceedingly minute eggs (.182 mm. in diameter) are 

 laid in great numbers in capsules secreted by the mollusk. These 



