FIDDLER-CRABS 283 



of fiddler-crabs occur on the Atlantic coast. They congregate in 

 immense numbers, and excavate their holes in convenient localities 

 above the reach of the tides on salt-marshes, far up the estuaries, and 

 along the mouths of rivers, even where the water is quite fresh. The 

 males have one claw very largely developed ; the other chela is small. 

 The former is likened to a fiddle, the latter to a bow, and this, toge- 

 ther with the waving motion of the large claw, gives them their popular 

 name. This comparatively enormous claw is a distinguishing feature by 

 which they are easily recognized without other description. The female 

 has claws of small and equal size. These crabs burrow holes in the 

 mud or sand half 

 an inch to two 

 inches in diameter 

 and a foot or more 

 in depth. The 

 upper part is nearly 

 perpendicular, be- 

 coming horizontal 

 below, with a cham- 

 ber at the end. One 

 species, U. minax, 

 constructs an arch- 

 way over the mouth 



of its burrOW, in Uea (Oelagimus) pngilator, the fiddler-crab; male. 



which it sits and 



surveys the surroundings, but quickly retreats when danger approaches. 

 The crab makes its burrow by scraping up the mud or sand and forming it 

 into pellets, which it carries under the three anterior walking-feet on the 

 under side, using the legs on the side moving forward, and the fourth 

 one on the other side, to climb out of the hole. After peering cautiously 

 about, the crab emerges, and carries its load four or five feet away 

 before dropping it ; then again looks about before quickly running 

 back ; and, finally, turning its stalked eyes, looks in all directions and 

 suddenly disappears, soon to return with another load. The burrows 

 cover considerable areas, and the crabs are so abundant that the marshes 

 and shores sometimes seem to be alive with them. When alarmed, they 

 lift the large claw and run sideways, after the manner of all crabs, to 

 their holes, and, as many are likely to retreat into the most convenient 

 one, the owner often finds his burrow occupied by other tenants, whom 

 he unceremoniously proceeds to pull out. U. minax ranges from southern 

 New England to Florida, and lives on salt-marshes farther away from 

 the sea than the others, and often where the water is quite fresh. It is 

 larger than the other species, and can be distinguished by a red patch at 

 the joints of the legs. It is a vegetarian in diet, living on small algse. 

 This is the species which constructs a little observation-house over the 

 mouth of its burrow. It can live out of water, and without food, for several 

 days. U. pugilator lives on sandy and muddy flats and beaches near 

 high-water mark, where the sand is compact and somewhat sheltered, 

 and ranges from Cape Cod to Florida. This species, like U. minax, is a 

 vegetarian. U. pugnax is exceedingly abundant on muddy banks and 

 ditches of salt-marshes, the banks being sometimes completely honey- 

 combed and undermined by them. It ranges from Cape Cod to Florida. 



