cr* 



FIG. 68. Association of a hermit crab and a 

 Ccelenterate. (From Parker and Has- 

 well.) 



FIG. 67. Physalia, the "Portu- 

 guese man-of-war." cr., 

 crest; #., polyp; />., 

 pneumatophore. (From 

 Parker and Haswell after 

 Huxley.) 



