THE CRUSTACEA OF NEW JERSEY. 449 



Abdominal segments in female two and one-half times broader 

 than in male. 



Color with carapace largely olivaceous above, paler be- 

 low. Large chelipeds often olive tinted, pale, pinkish, brownish 

 or yellowish on fingers. Legs brownish, spotted or dotted 

 with darker, and become paler on dactyls. Eye-stalks brown, 

 eyes darker. Abdominal segments pale brown, often dotted with 

 darker. Length of carapace 16 mm., width 22 mm. 



Remarks. — ^Distributed from Cape Cod tO' the Gulf of 

 Mexico. It lives along our sandy beaches near high-water mark, 

 usually in somewhat sheltered locations and where the sand is 

 compact or rather hardened. Great numbers are sometimes 

 met with in favored localities. They live in burrows or holes, 

 which they dig in the sand. The holes are dug by carrying 

 up little pellets of moist sand, and running several feet from 

 the burrow before they drop it. Before proceeding back to 

 their burrow they usually pause a short time as if to apprehend 

 danger, then run back to the burrow, and after giving a last 

 look about, disappear in the hole. Their work is carried on 

 at all favorable hours of the day or night, according to the 

 weather and as the tide is out. The colonies of these animals 

 are quite interesting, the little creatures moving about actively 

 over the sand sidewise, suddenly halting and retracing their 

 steps as any disturbance may require, or others may be seen 

 looking out cautiously from their burrows. Sometimes these 

 communities extend for several acres. The diameter of the 

 burrow is usually small, or just enough to admit the body 

 of the crab. They extend down a foot or more in a vertical 

 direction, and become more or less horizontal with an excava- 

 tion at the lower end. Often if the under strata of soil, or that 

 below the sand is dark or black, the pellets carried up from 

 the burrows form in contrast to the general pale surroundings. 

 When leaving the burrow the male usually emerges with the 

 large cheliped folded and forward. According to Prof. S. L 

 Smith it is a vegetarian, feeding upon the minute algae which 

 grow upon the moist sand. The males use only the small claw 

 in feeding, picking up the bits of algae very daintily. The 



29 MU 



