36 NATICA. 



Natica, whilst the tongue bores a circular hole through the shell 

 near its beak. The egg-case, like that of N. duplicata, is a com- 

 mon sea-shore object. 



N. triseriata^ Say (fig. 16) is a color-variety of the young of 

 this species ; it has three spiral series of oblique, short chestnut 

 streaks, under an olive-gray epidermis. In this state the species 

 resembles some of the typical Naticas in coloration. As the 

 shell grows larger the markings become more obscure, so that it 

 is rare to find a specimen an inch in diameter in which any trace 

 of them remains. In other j'oung specimens there are never 

 any markings at any stage of growth. N. ampullaria, Lam., 

 referred b}' authors to several species, reall}' appears to belong to 

 this ; but there seems to be no good reason for reviving it at this 

 late day. N. ponium, Phil. (fig. 20) appears to be a synonj^m ; 

 its locality is unknown. 



N. PAPYRACEA, Sowb. PL 13, fig. 14. 



Shell thin, globose, yellowish white, obscurely- two-banded, 



umbilicus narrow, interior of aperture and columella flesh-color. 



Length, 1"4 inches. 



Hab. unknown. 



Said to resemble the European Helix pomum. It is probably 



the young of one of the preceding species — perhaps of N. Lewisii. 



N. LEVicuLA, Yerrill. PI. 13, fig. 17. 



Shell thin and light, globose, with deeply impressed sutures, 

 columellar lip nearly vertical, very slightly callously expanded 

 above, so as to encroach somewhat on the narrow umbilicus. 



Length, 40 mill. 



Maine., 3Iassachu^ef.ts ; deep water. 



Much thinner, with more rounded whorls and diff"erent colu- 

 mella than N. heros. It is very rare, and has only been obtained 

 during recent years by dredging. 



N. GLOBOSA, Jeff'reys. PL 14, fig. 34. 



Globular, thin and fragile, semitransparent, glossy, whitish, 

 suture rather deep, umbilicus narrow. Length, 2*5 mill. 



Morocco an^. Gape Verd Is. (Talisman Exped., 1192-1980 fms.). 



I introduce this little species here, because of its remarkably 

 suggestive resemblance to the preceding one, of which it may 

 possibly be the young. 



