I50 



MOLLUSCA 



The oyster [Ostred) "* is sessile and lacks a foot. It is used in 

 America more than any other shell fish and has been popular in spite 

 of the occasional occurrence of typhoid carried by freshened oysters. 

 The practice of transporting oysters from relatively clean salt water 

 to the mouths oi polluted t'xy&vs and there keeping them " floating " 

 until they have become bloated and swollen and have lost their 

 true ocean flavor is one that has brought oyster dealers additional 

 money when they sold oysters by the quart, but has lost many lives 

 from the typhoid germs collected. 



Fig. 66. Mussel with Buddha images. Chidester. {Sci. Am. Supply 191 5.) 



The window-glass shell ( Placuna placenta) is used in the tropics 

 for windows in churches and other buildings. Reese reports that 

 the demand for " window pane " shell in the Philippine Islands 

 has recently exceeded the supply, so that the Philippine Bureau of 

 Science planted new beds. 



The wood-boring ship-worms {Teredo and Bankid) were in early 

 days a formidable enemy of wooden ships. Recently it was dis- 

 covered that the wood-boring ship-worm, Teredo navalis^ was doing 



^ Brooks, W. K. 1905. The Oyster. Bait. 



