MOLLUSCA 175 



water from Massachusetts to Florida. Not common 



in New Jersey coastal waters but occasionally 

 dredged off shore. 



Natica clausa Broderip and Sowerby 



A small species with a white callus in the um- 

 bilicus; operculum (lid) calcareous instead of horny 

 (as in heros, triseriata and duplicata). A northern 

 species very rare in Xew Jersey. 



Sinum perspectivum Say (Ear Shell) 



(Sigaretus perspectivus Say) 



PLATE XVIII. Fig. 3 



A flat ear-shaped shell which is really a modi- 

 fied Natica. Common on southern beaches but only 

 a few have been found in New Jersey (Atlantic 

 City, Wildwood, Two Mile Beach and Cape May); 

 some of these may be fossils. 



Crepidula fornicata Liiine (Boat Shell; Slipper 



Limpet ) 



PLATE XVIII. Fig. 1 



One of the most easily recognized shells of the 

 Xew Jersey beaches. The top of the shell is pointed 

 and the spire is merely an inconspicuous apex closely 

 pressed against the shell. The top part of the shell 

 is rounded giving it a boat-like appearance. A 

 shelf covering the upper part of the aperture 



