11 IK THORNY OYSTER. 



421 



The File-shell can pass through the water with some rapidity, urging itself along by 

 the sharp closing of its valves. Its color is crimson, with the exception of the mantle, 



LIMA.-JL/ma hlaas. 



which is orange. The shell is pure white, so that a living and healthy specimen is a 

 most beautiful creature. 



THORNY OYSTER. Spoadylus AmeHcaaus. 



A VERY curious example of this family is found in the THORNY OYSTER, a species 

 that is remarkable for the singularly long projections from the shell. The object of these 



