CO AMERICAN MARINE CONCIIOLOGY. 



Genus NEVEEITA, Risso. 

 Moll. Eur. Merid., iv. 149. 1826. 



1. N. duplicata, Say. Fig. 101. 



(JSfatica.) Joum. Phila. Acad. Nat. Sci., ii. 247. 1822. 

 Shell solid, subglobose ; whorls five, somewhat convexly flat- 

 tened above; aperture oval, oblique; umbilicus irregular, with a 

 deep furrow, and almost entirely covered by a thick callus. 

 Color ashen-gray, within deep chestnut-brown; callus of the same 

 color. 



Length 25-50, diam. 27-55 mill. 



New England to Georgia. 



Genus MAMMA, Klein. 



Ostracol. 21. 1753. 

 1. M. immaculata, Totten. Fig. 102. 



(Natica.) Amer. Journ. Sci., xxviii. 357 f. 6. 1835. 

 Shell small, solid, longitudinally suboval. Whorl about five, 

 the upper ones very slightly convex; apex short and pointed, su- 

 ture not impressed ; the body-whorl convex and elongated be- 

 neath. Aperture narrow, regularly and somewhat acutely curved 

 at the base. Umbilicus rounded and deep, scarcely modified by 

 the callus, which is not veiy copious, but forms a deposit under 

 the upper part of the lip, and causes a white spiral line to appear 

 externally just below the suture. Epidermis thin, greenish-yellow, 

 beneath milk white. 



Length 7, diam. 5.5 mill. 



Maine to Neio York. 



Genus BTJLBUS, Brown. 

 Proc. Geol. Soc, iii. 119. 1839. 

 1. B. Smithii, Brown. Fig. 103. 



Natica flava, Gould, Am. Journ. Science, xxxviii. 196. 1840. 

 IS'atica aperta, Lovcu, Index Moll. Scand. 1846. 



Shell globular, inflated, thin and light; whorls four, rounded, 

 slightly compressed above near the suture, with very minute in- 

 cremental and revolving stria? ; spire little elevated ; pillar-lip 

 with a curve in its middle ; the callus contracting and obliterating 

 the umbilicus, which is deeply indented ; epidermis light yellowish, 

 white underneath ; callus ivory white. 



Maine northwards {Eur.). 



