Handbook of Paleontology 167 



coasts, are the English Whelk, a variety of the Sand 

 Collar Snail (Lunatia heros), species of Boat or Decker 

 Shells. South of Cape Cod, in shallow water of muddy 

 bays and well-sheltered places, the little Bubble Shells 

 (H amine a solitaria) may often be found in considerable 

 numbers. The shells are very small, thin and fragile, 

 shining bluish white or brownish in color. There is no 

 spire, the aperture is as long as the shell, which is marked 

 by revolving grooves across which the irregular growth 

 lines cut. Related species of this form are found on the 

 Florida and California coasts. The Oyster Drill is 

 found associated with the oyster beds. The Elephant's 

 Tooth Shells which are found cast up on beaches during 

 storms range from moderate to deep waters and live 

 buried in mud. 



Many of the bivalves are of the same species as those 

 inhabiting sandy bottoms, such as the Soft-shell Clam, 

 the Quahaug, the Razor Shell, the Swimming Clam, 

 Angel's Wings, Common Edible Mussel, the little Ma- 

 comas etc. Also are found the American Oyster, Ribbed 

 Mussels, species of Scallops, the small Ledas, Yoldias and 

 Nut Shells. Perhaps the mussels and oysters are the 

 most conspicuous forms of muddy bottoms. The Edible 

 Mussel grows in patches, "beds or banks," of consider- 

 able extent on the muddy bottoms of bays and sounds, 

 and it also occurs on open coasts. The Ribbed Mussel 

 (Modiola plic alula) is a brackish- water species found 

 between tide limits which ranges from Nova Scotia to 

 Georgia. It inhabits tidal waters of streams, sheltered 

 muddy reaches among reeds and tidal flats, and there is 

 probably no muddy reach of land, exposed at low tide, 

 between Maine and the Carolinas which is not occupied 

 by this species. There are other species of mussels along 



