NATICTDjE. 13 



The Velutinas resemble the pulmoniferous genus Otina, but 

 are strictly marine. Sometimes they are met with far out at 

 sea, but usually live among stones near low-tide. Boreal. V. 

 Isevigata, Pennant. 



? Catinella, Stache, is a synonym. 



Section LIMNERIA, H. and A. Adams, 1853. 



Spire more elevated, peristome not continuous, columella 

 subcanaliculate. F. undata, Brown. 



Morvillia, Gray, 1857, is a synonym. 



Section VELUTELLA, Gray, 1847. 



Shell in most part covered by the mantle, very thin, flexible, 

 with short spire ; peristome continuous, thickened. V. Jlexilis, 

 Montg. 



Section LEPTONOTIS, Conrad, 1866. 



Margin of the aperture remarkably expanded, surpassing tho 

 spire. V. expansa, Whitfield. Eocene. Alabama. 



The shell is minute, and may be embryonic. 



SC^EVOGYRA, Whitfield, 1817. Struc. and Syst. Conch., iii, 350. 

 LYOSOMA, White, 1883. Struc. and Syst. Conch., iii, 350. 



These two fossil groups, of doubtful relationships, may 

 possibly be members of the Naticidn-. 



Subfamily III. Vanikoridde. 

 Genus VANIKORO, Quoy and Gaimard, 1832. 



Shell subglobose, external, white, with a velvety epidermis, 

 surface striate, costate or decussate, umbilicated, without a trace 

 of callus in the umbilicus ; spire not produced; aperture semi- 

 lunar, outer lip simple. 



Animal described in the subfamil}'. Operculum thin, corneous, 

 with apical nucleus, not spiral (PL 1, figs. 16, 17). 



A few species are found about corals in warm seas; fossil, 

 commences with secondary strata. 



About equally well-known under the later and perhaps more 

 acceptable name of Narica, Recluz, 1841. Leucotis, Swainson, 

 1840, and Merria, Gray, 1842, are also synonyms. 



Section YANIKOROPSIS, Meek, 1876. 



Shell subglobose, thick, body-whorl large, spire low ; imper- 



