MALACOSTRACA. DECAPODA. 275 



Gecarcinusy* the Land-crabs. 



These have a heart-shaped shell, appearing as if 

 cut off behind ; the eyes are club-shaped ; the two 

 middle pairs of legs are the longest. They are 

 common in the tropical parts of America and the 

 West Indies, where their highly curious habits have 

 attracted the admiration of travellers. Their usual 

 residence is in burrows, which they are said to close 

 up during the time when they are casting their shell 

 within. At this season, while the crust is yet soft, 

 their flesh is highly esteemed, though sometimes 

 unwholesome. Early in summer, when the rains 

 descend, they leave the mountains in order to seek 

 the sea, where they may deposit their eggs. In 

 these annual migrations, they accumulate in such 

 hosts, that the roads and fields are covered with them. 

 Like a great army strictly disciplined, they march 

 on in a straight line without breaking their ranks ; 

 they determinately scale houses, cross rivers, and 

 surmount every obstacle. Frequently they enter 

 the houses, making a noise like that of rats, and 

 in the gardens commit great havoc, destroying fruit 

 with their powerful claws. Their march is chiefly 

 in the night, and they halt with great regularity at 

 certain intervals. When they reach the sea, after 

 bathing themselves three or four times, they retire 

 to the neighbouring woods, where they repose a 

 while ; then the females return to the sea and de- 



* rJ, ge, earth, and xagxivo;, karkinos, a crab. 



