THE BEATING OP THE JACKS. 107 



noted. The sun-shells are in shape much like 

 the soft clams of the North, but wonderfully 

 polished, and ornamented with ray-markings 

 that spring from near the hinge, growing wider 

 as they reach the lip of the shell. They were 

 found at the bottom of a round hole about two 

 inches in diameter and two feet deep, and were 

 invariably dead, with a hole bored in each, 

 showing the death to be the work of some para- 

 sitic shell. 



" This looks as if the natica, or whelk, had 

 been at work here," said the doctor. " It has a 

 wonderful arrangement of teeth, or grinders, 

 with which it bores circular holes in the clams, 

 and devours them at leisure. By the way, the 

 natica is a nest-builder, such as we were men- 

 tioning. Those collar-shaped pieces of sand that 

 you have found on the Northern beaches are the 

 nests in which the natica deposits its eggs." 



Here a shout from Long John, who with 

 Bob Rand was out on the sea-wall, caused the 

 boys to look up quickly. 



" Look out yonder," shouted Long John ; 

 "the jacks are beating !" 



