99 



NATICA patula. 

 TAB. CCCLXXIII. 



Three lower Jigures. 



Spec. Char. Hemisphosroidal, smooth, spire 

 small, depressed; mnbilicus open containing 

 a spiral ridge. 



The last whorl is very large and expanded, so as to give 

 the entire shell the form of half a flatted spha;roid cut 

 along its axis. The surface is smooth, or so obscurely 

 striated that it is difficult to persuade oneself that the 

 striae are worn away, I speak of concentric striae ; the 

 lines of growth are visible enough. The umbilicus is 

 large, and not quite half filled by a large callus, that 

 does not spread over it, and is accompanied by a smaller 

 one, which forms a spiral ridge. The spire occupies less 

 than a fifth of the shell, and is barely relieved from the 

 o-eneral surface of the last whorl. 



Found in the Suff'olk Crag at Ipswich, by Mrs. Cob- 

 bold, generally about an inch wide, but sometimes, as 

 specimens lent me by the Rev. G. R. Leathes prove, 

 an inch and a half; the lower figures exhibit these 

 specimens. 



NATICA striata. 

 TAB. CCCLXXIII. 



Two upper Jigures. 

 Spec. Char. Subhemisphoerical, smooth ; spire 

 small, depressed umbilicus open; base con- 

 centrically striated. 



Gtreatly resembling the last, but not so much expan- 

 ded ; the spire is rather more prominent, the concentric 

 striee are impressed, but as they are liable to be lost by 



