34 



THE LINGULA. 



be protruded to a considerable distance out of the shell, 

 acting either the part of oars in slightly altering the 

 position of the body, or rather of sensitive t-entacula, 

 and therefore to be regarded as organs of touch and 

 of seizure. In lingula these fringed arms are mo- 

 derately developed, as seen in the annexed outline, 

 which represents the animal with the shell rem-oved; 

 the mouth, a, is a simple orifice at the apex of an 

 elevated tubercle ; and on each side are the fringed 

 arms, b b. 



The Lingula. 



