Handbook of Paleontology 151 



New Jersey coast and in Long Island sound on sandy 

 and gravelly bottoms. They are pear-shaped and 

 about six inches long. The Knobbed Whelk (Fulgur 

 carica) is characterized by knoblike protuberances 

 around the shoulder of the body whorl ; the Channeled 

 Whelk (Sycotypus canaliculatus) lacks these, but has 

 a deep channel at the suture of the spire. Both prey 

 upon other mollusks and are destructive to clams and 

 oysters. Another characteristic snail that is cast upon 

 the beach looks like a worm with a calcareous cover- 

 ing {Vermicularia spirata). It starts like a gastropod 

 shell, then the whorls become separated and seem to 

 wander in an aimless way. Many of these shells are 

 found grouped together in an inextricable mass. 

 These forms inhabit shallow water from New Eng- 

 land to Florida. The shells are ashy white or rufous. 

 The Oyster Drill (Uro salpinx cinera) is also washed 

 in from the oyster beds. There are several species 

 on the eastern coast of the United States. This spe- 

 cies has a wide range from Florida to Cape Cod. Its 

 original home was in Chesapeake bay and it was trans- 

 planted with the oyster spat. The shell is dingy gray 

 in color; a dozen or more riblike undulations cross 

 the whorls which also bear numerous revolving striae ; 

 the spire is high and the anterior canal is produced and 

 of a yellowish brown color within. Boat Shells (Cre- 

 pidula) are cast upon the beaches attached to dead 

 shells, horseshoe crabs, stones etc. The largest spe- 

 cies (C. fomicata) is exceedingly common on the At- 

 lantic coast, ranging from the West Indies to Nova 

 Scotia. They are also known as "deckers" or "slipper 

 limpets," and are degenerate, scalelike snails that fit 

 closely to the surface to which they are attached, made 



