230 Dzvellers of the Sea and Shore 



seen the devious course of many well-marked trails over 

 the mud, at one end of which the vigorous worker 

 reveals Itself by throwing up a miniature cloud of silt 

 as It uses Its gill plates to sweep the loosened particles 

 to the rear. The telltale trails are of various sizes, 

 ranging from the breadth of my little finger to the 

 width of my hand. 



But most Interesting Is the behavior of the adults. 

 For them I must look elsewhere. On the wide stretch 

 of gravel, sand, and comminuted shells that lies between 

 the pool and the waters of the harbor, are sundry low 

 mounds scattered here and there. They are of the 

 usual size and general appearance that would be caused 

 by throwing up a shovel full of sand. They are not so 

 caused, however; they are produced by mating horse- 

 shoe crabs. Each tumulus denotes the presence of a 

 pair who, having been stranded here by the falling tide, 

 pushed their way underneath partly to make a deposi- 

 tory for the eggs, but also ostensibly to conceal them- 

 selves. Their efforts to conceal themselves, however, 

 are not often successful; they are suggestive of the 

 fabled ostrich, since In many Instances It Is the female 

 only who hides her head In the sand. She Is the larger 

 of the two, and her smaller mate may be seen Immedi- 

 ately In the rear with both his heavy claws tightly 

 gripping the two terminal points of her abdomen. 



The mating couples do not all take advantage of the 

 tide to reach this strand. Occasionally a female, seem- 

 ingly unable longer to withstand the urgency of mater- 

 nal demands, will leave the water when It Is low, and 

 proceed up the shore, dragging after her an attendant 

 male with his hold firmly fixed on her abdominal tips. 



