162 New York State Museum 



especially abundant on the sandy shores of New Eng- 

 land north of Cape Cod and also farther south in 

 Chesapeake bay. The King or Horseshoe Crab is not 

 a true crab, but is related to the spiders and scorpions 

 and extinct eurypterids. The adult animal is about 

 one foot broad and two feet long. There is a crescent 

 shaped, domelike shell over the head and trunk with 

 two furrows along the sides of the back. The abdo- 

 men ends in a long sharp movable spine. There are 

 large lateral eyes and two small median eyes. In ap- 

 pearance the head region resembles that of the long 

 extinct trilobites. The Horseshoe Crab ranges along 

 the Atlantic coast from Maine to Yucatan, and lives 

 on sandy and muddy shores below low-water mark 

 where it burrows beneath the surface. There are few 

 existing species of Limulus, one on our coast and sev- 

 eral on the coast of Asia. 



Muddy Bottoms 



The deposition of mud implies shelter of some kind, 

 such as estuaries, inlets, mouths of creeks etc. Muddy 

 bottoms are inhabited by a considerable number of 

 species that find their true home in such localities, 

 such as burrowing and tube-dwelling species. Then 

 there are some forms that crawl or swim about over 

 the surface or conceal themselves in the superficial 

 layers of mud. A variety of crustaceans, especially 

 crabs, occurs here; mollusks, especially bivalves, 

 are abundant and there are numerous species of 

 burrowing and tube-dwelling worms, some occur- 

 ring in great numbers. Muddy bottoms vary in their 

 faunas according to their situations, that is, whether 

 in estuaries, bays or sounds or along open coast. Mud 



