844 NATICID^. 



Natica pusilla. 



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

 Stimpson, Shells of New England, 4-3 ; Check Lists, 5 ; not of Gould, Inv. 1st cd. 



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

 T one or two obsolete, dilated, revolving bands ; columella 

 callous ; callus pressed laterally into the umbilicus, whitish ; 

 ^'.pusilla. y^Yi-ih\\\Q\\& nearly closed and consisting only of an arcuated, 

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

 Inhabits the southern coast. (Say.') 

 Buzzard's Bay, three to eight fathoms (^Stimpson). 



Oeniis MAMITIA, Klein. 1753. 



Operculum large, horny, simple. 



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

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

 oblique, thickened, callous ; umljilicus 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, glossy, 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. 

 Aliimma? immaculata, Stimpson, Check Lists, 5. 



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

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

 j,. g^^ less, lines of growth faintly perceptible ; whorls about five, 

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

 pressed ; the lower whorl convex and rounded, prolonged at 

 the base ; aperture narrow oval, rather acutely curved at 

 base ; outer lip sharp, inner margin coated Avith 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 



