194 ANIMALS OF THE SEASHORE 



Terebra dislocata Say (Spiral; Staircase Shell) 



PLATE XVIII. Fig. 10 



A spiral shell up to 2 inches long; numerous 

 minute radiating- lines; prominently ribbed with 

 numerous revolving grooves. 



Although this species is not known alive north 

 of North Carolina (or possibly Maryland), shells 

 are occasionally found on the New Jersey beaches. 

 The species is frequent in the Pleistocene (inter- 

 glacial) deposits and it is probable that the beach 

 shells were transported from some such deposit. 



Terebra concava Say 



PLATE XVIII. Fig. 8, 9 



Distinguished from the above because the 

 radiating lines or nodules do not extend across the 

 grooves. Similar distribution as T. dislocata but not 

 quite as common in the Pleistocene of New Jersey. 



Mangelia cerina Kurtz and Stimpson 



This small species, although reported from 

 Massachusetts to Florida in 3 to 10 fathoms, has 

 not been found alive in New Jersey waters; known 

 from the Pleistocene (interglacial) deposits at Two 

 Mile Beach. 



