GEOGRA PHICA L DIS TRIE UTION. 



147 



TABLE EXPRESSING THE RELATIONS BETWEEN THE DIFFER. 



ENCES IN STRUCTURE OF THE GASTROPODA AND 



DIFFERENT CONDITIONS OF ENVIRONMENT. 



NOTE. The stars opposite the name of each group indicate the kind of 

 environment to which the genera of the group are adapted. 



Summary of Results. This analysis of the distribution of 

 the various types of Gastropods may be summarized as follows : 



The organic structure of Gastropods is such that it is 

 capable of adjustment to all the conditions of environment 

 found inhabited by living things on the face of the earth, or 

 in the waters under the earth. 



