MOLLUSKS IN GENERAL 



231 



she// 



Ap/rrra/ 

 //7 -f-i/te 



5/phons 



B 



Fig. 142. — Shipworm, Teredo navalis Linnaeus. A, section of a block of wood showing 

 parts of several empty tunnels and one containing an animal. The whole is divided, and 

 only the two ends shown to allow it to come within the limits of the figure. {From Cooke, 

 "Cambridge Natural History," after Mobius, by the courtesy of The Macmillan Company.) 

 Natural size. B, the shell, mounted in position at the end of a tunnel, lateral view. {From 

 Miller, Univ. of California Pub. in Zool., vol. 26, by the courtesy of the University of Cali- 

 fornia Press.) X 53^. 



