32 NATICA. 



and only leaving an arcuated linear opening; operculum cal- 

 careous. Length, 6 mill. 



Southern Coast of the United States; 



Buzzards Bay, 3 to 8 fms. (Stimpson). 

 This is not N. pUsilla of Reeve's " Iconica." 



Section STIGMAULAX, Morch, 1852. 

 N. SULCATA, Born. PI. 9, fig. To. 



Largely umbilicated, partly filled by an inferior entering 

 callus ; cancellated by revolving and longitudinal close grooves, 

 often pitted at their crossings ; white, sometimes banded and 

 mottled with fulvous orange. Length, 20 mill. 



West Indies. 



The revolving grooves are sometimes very faint, in other 

 specimens as strong as the longitudinal ones. Other names for 

 the species are N. cancellata, Gmelin, N. rugosa, Chemn., N. 

 costata, Menke. 



N. SEMISULCATA, Gray. PI. 9, fig. T4. 



Deepl3' and rather widely umbilicated, umbilicus bounded by 

 an angle, suture excavated, whorls slantingly flattened above; 

 polished white, encircled superiorly by five or six linear 

 grooves. Length, 14 mill. 



West Indies. 



Is possibly a Mamma. I do not know the operculum. 



Subgenus NEVERITA, Risso, 1826. 

 Section NEVERITA (typical). 



X. AMPLA, Phil. PI. 10, figs. 81-83, 85, 86 ; PI. 11, figs. 91-03 ; 

 PI. 12, fig. 6. 



Depressed globose, indistinctly spirally engraved, a little 

 depressed below the suture ; umbilicus very wide, spirally striate, 

 and usually two- or three-ridged, umbilical callus transversely 

 deeply grooved in the middle, reflected over the upper portion 

 of the umbilicus, rather small ; color light flesh or yellowish 

 brown, earlier whorls often livid, interior and callus light choco- 

 late. Length, 2-2*5 inches. 



Indian Ocean, China, Japan, Australia, Mauritius. 



The numerous species here united have received from Sowerby 



