MOLLUSCA 181 



ally white or olive in color. Similar habits as L. 

 6btussaba\ known from Cape May, N. J. to Labrador 

 and Hudson Bay. 



Lacuna vincta Montagu 



Fig. 28 C 



Shell less than % inch in length, usually purp- 

 lish in color. The umbilicus forms a lengthened 

 groove along the columella. A northern shell known 

 from Labrador to New Jersey. It is frequently 

 common on Sea Lettuce (Ulva) between the tides 

 and in shallow water. It is inconspicuous on the 

 living sea weed, and may best be found by drying 

 some, and then shaking it to obtain the small shells 

 that were adhering to the weed; often associated 

 with Paludestrina minuta. Cape May is the southern 

 limit. 



Cerithiopsis subulata Montagu 

 (C. emersoni Adams) 



PLATE XX. Fig. 9 



A small gastropod known from 2 to 15 fathoms 

 between Massachusetts and the West Indies. Not 

 seen alive in New Jersey waters, but occasionally 

 found in the Pleistocene deposits or washed upon 

 the beach. 



