48 Lessons in Zoology. 



cannot expel an intrader, he takes this way of coveting it 

 up and thus freeing himself from the irritation it caused. 

 Near the impressions of the adductor muscles (Fig. 8, 

 aa and pa) are two smaller prints (ap and pp) made by 

 the muscles which move the foot. The pallial line (jo) 

 runs from the anterior to the posterior adductor, but with- 

 out any sinus. This lack is explained when we see that 

 this clam, the back part of whose body is never buried in 

 the sand, has no long, muscular siphon, because it nee(U 

 none. The mantle, open everywhere else, is simply united 

 enough at the feiphonto make two very short tubes, which 

 are always in the water. 



The parts of the body hare the same relative poaition as in the 

 aalt-water clam, bat the palpi, instead of hanging freely, are simple 

 folds. 



