1888.] NATURAL SCIENCES OF PHILADELPHIA. 835 



the sand over which it was found hopping. These grasshoppers 

 probably furnish food for the S2)iders, but the only remains of animal 

 food found within the burrows were those of a large brownish 

 beetle, several specimens of which were picked up on the beach. 



Among the other denizens of the beach are ants of a small species 

 whose nests are well nigh numberless. They are made in the sand, 

 but it seemed that the little creatures must have considerable diffi- 

 culty in preserving their galleries and rooms from continual destruc- 

 tion by the caving in of the incoherent particles. However, they do 

 manage it, although in digging to find the character of their galleries 

 the speaker could not so manipulate the sand as to prevent it from 

 tumbling into the formicaries and thus hindering him from studying 

 of the interior. He did not know what the ants feed upon, although 

 he found some of them engaged at the carcass of one of the brown 

 beetles above alluded to, and no doubt the flotsam of the sea thrown 

 upon the beach affords them abundant material for food. He made 

 a number of visits to these sand dunes both by day and night, pro- 

 longing his stay to a late hour in the evening in order to discover 

 .something of the outdoor habits of the colony of Turret spiders, but 

 succeeded in learning very little that is new. 



A lady artist who with some companions was sketching upon the 

 beach, (for Annisquam is a favorite field for painters,) informed Dr. 

 McCook that about dusk a large spider was seen moving over the 

 sand towards the water. Supposing this to be one of the above colony 

 the question at once arose, do they come down from the dunes to the 

 wide flat stretch of beach, that is covered at flood and that is uncov- 

 ered at ebbtide, in order to prey upon the sea life that may be left 

 at the retiring of the waters? Two afternoons and nights were spent 

 from five until nine and ten P. M.endeavoring to solve this prob- 

 lem, but without any results. He then tried another method. Visit- 

 ing the beach in day-time he captured a couple of mature spiders ; 

 placed them upon a smooth stretch of clean sand and permitted them, 

 and when necessary compelled them by prodding, to move over the 



ft B surface. They left upon the sand a 



, ' *> peculiar track which is here roughly 



I I y« f represented by two sections taken 



•*• / ^» from different parts of the trail. 



*• •• , Having made a careful sketch of 



t these foot prints he returned early 

 I next morning and made a careful 

 examination of the beach for a cou- 

 ' • * siderable distance along the shore. 



Many tracks of various kinds of creatures, including such insects 

 as beetles and grasshoppers, and also of some small vertebrate 

 animals, were found. 



But by far the greatest number were tracks which correspon- 

 ded precisely with those made on the previous day by the captured 

 Arenicolas. Multitudes of these were seen upon the sand covering 

 the surface and slopes of the hills and extending to the very border 



•r .i. y 



