CRABS, HERMIT-CRABS, AND OTHER CRUSTACEANS. 143 



to enable it to retain its hold on the shell, and the other ab- 

 dominal appendages are rudimentary or wanting on the right 

 side, or that side which comes most against the inside of the 

 shell, as if they had been worn off. Wherever the creature 

 goes, it draffs the shell after it as a house. 



O " O 



FIG. 133. HEEMIT-CRAB REMOVED FROM ITS SHELL: r, Hardened Ridge which bears against 

 the Inner Edge of the Aperture of the Shell ; a, a, Appendages to which the Eggs are 



attached. 







As the hermit-crab grows, it passes through the same 

 features of moulting which characterize the crustaceans gen- 

 erally. The shell which protects its soft defenseless abdomen 

 has, of course, no power of growth, and is abandoned when 



