38 



BKANCH MOLLUSt'A. 



Mai' le us vul ga' ris. Hammer-oyster. 



The Hammer-oyster, of the Indian Ocean, presents 

 one of those singular forms seemingly designed to puzzle 



naturalists in endeavoring to ac- 

 count for the utility of the anom- 

 alous outgrowths. 



The Mussels are widely dis- 

 tributed along the marine shores, 

 and in some places, are used in 

 large quantities for food. They 

 are peculiar, in that the water 

 enters the mantle chamber 

 through a short tube, the incur- 

 rent siphon, and leaves it by an- 

 other, the excurrent siphon. The 

 so-called foot has the power of 

 spinning a number of threads, 

 the 7>//.s.sv/x, which it- can throw 

 out one after another and then contract them, a slow 



F 



JUi/t'ltus e du' Us. Mussel. 

 F, Foot. B, Byssus. 



