THE HABITS OF FIDDLER-CRABS. 119 



to the top of his hole so that he shut himself inside. On another 

 occasion a nervous little female, after hastily carrying 3 loads 

 of dirt from her burrow and plastering a couple of pieces of 

 soft mud around her doorway, went part way into her burrow, 

 and by scraping with the legs of one side (fig. 3) gradually 

 decreased the size of the opening until there was barely room 

 enough to draw her legs inside. She then shut herself in by 

 pushing up soft mud from below. 



When a fiddler wishes to open a burrow that has been sealed, 

 it pulls the plug down inside. The plug must usually be left 

 there for it was seldom brought out within a reasonable time 

 in the numerous instances observed. Once a large IJca forcipata 

 was seen to open his burrow by simply walking out of it, the 

 plug being pushed to one side. 



Fiddlers are very cleanly in their habits and often scrape 

 themselves vdth the small chelae or with the walking legs when, 

 in burrowing or in some other way, they have accumulated dirt 

 on any part of their body. They are particularly careful of the 

 eyes and eyestalks and these organs are often folded into their 

 sockets and rubbed a few times. Mud or debris is not allowed 

 to accumulate about the mouths of the burrows. Fiddlers have 

 often been seen moving such matter to some little distance where 

 it was cast aside or pushed down the holes of other crabs. 



Both sexes move sideways in entei-ing the burrow, and the 

 males more often have the large chela uppermost as they dis- 

 appear. So far as the writer observed they always emerge in 

 the same position as they enter; that is, the body is not turned 

 around in the burrow. The holes are usually of uniform diam- 

 eter, though they may be slightly enlarged at the bottom and 

 occasionally turn off in a horizontal direction. They vary in 

 depth from about 16 to 75 centimeters, and usually have water 

 standing in the deeper parts, even when the tide is out. 



PLACE ASSOCIATION. 



A fiddler usually does not wander more than a meter and a 

 half from his home and is ever ready to dart into it at the 

 slightest provocation. Nevertheless, the writer observed a few 

 instances in which particular individuals wandered 4.2, 4.5, 9, 

 9, and 12 meters from their respective burrows and returned. 

 One peculiarly marked Uca marionis nitida, for no apparent 

 reason, dug a new hole 4.5 meters from where he had first been 

 observed; and a certain V. rathhunse, whose burrow had been 

 inadvertently closed by the writer as he walked over it, dug a 

 new hole 2.4 meters away; but such cases were unusual, and 



