344 NATICID^. 



Natica pusilla. 



Natica pusilla, Sat, Journ. Ac. Nat. Sc. Phila. ii. 257 (1822) ; 1st ed. Bikxey, 87.— 

 JStimpson, Shells of New England, 43 ; Check Lists, 5 ; not of Gould, Inv. 1st ed. 



Fig. 613. Shell thin, sub-oval, cinereous or rufous, with sometimes 

 one or two obsolete, dilated, revolving bands ; columella 

 callous ; callus pressed laterally into the umbilicus, whitish ; 

 N.T'usdia. ^^i^-iijiiicyg nearly closed and consisting only of an arcuated, 

 linear, vertical aperture. Length, about one fourth of an inch. 

 Inhabits the southern coast. ( »SV/7/.) 

 Buzzard's Bay, three to eight fathoms QStimpson). 



Oeniis MAItII?IA, Klein. 1753. 



Operculum large, horny, simple. 



Shell ovate or sub-ovate, solid, smooth, usually without epidermis ; 

 spire small, acute, whorls simple ; aperture semicircular ; inner lip 

 oblique, thickened, callous ; umbilicus funiculate ; columella adherent 

 to, and spirally contorted in, the umbilicus ; the apex more or less 

 dilated, convex, and rounded. 



Mamma? immaculata. 



Fig. 168. 



Shell small, sub-ovate, solid, bluish-white, spotless, g'loss}^, umbilicus free. 



Natica immaculata, Totten, Sillim. Journ. xxviii. 351, fig. 6. — Gould, Inv. 1st ed. 234, 



fig. 168— De Kay, N. Y. Moll. 122, pi. 7, fig. 146. 

 Mamma? immaculata, Stimpsox, Check Lists, 5. 



Shell sub-ovate, extremities rather pointed, solid, milk-white, and 

 glossy when deprived of its thin, greenish-yellow epidermis ; spot- 

 j,. ^^^^ less, lines of growth faintly perceptible ; whorls al)Out five, 

 the spire very short and pointed, and the suture not im- 

 pressed ; the lower Avhorl convex and rounded, prolonged at 

 the base ; aperture narrow oval, rather acutely curved at 

 base ; outer lip sharp, inner margin coated with ivory-white 

 callus, not modifying the umbilicus, but extending along the 

 margin to its posterior limit ; at the posterior angle of the aperture 

 it is much thickened, and, running along under the junction of the 

 whorls, causes a white spiral line to appear externally, just below 



