239 



general form is somewhat like N. signata. It is remarkable for 

 its nearly circular, cup-shaped aperture, its shining black, finely- 

 granulated concave pillar, and its gray, minutely mosaic surface 

 produced by the white lines crossing its ridges. 



Natica Lewisii. Testa magnifica, solidiuscula, conico-globo- 

 sa, albida, epidermide sordide stramineo induta, lineis minimis, 

 confertissimis, flexuosis cincta ; anfr. 6 ventricosis postice valde 

 constrictis : apertura obovata, ampla ; callo copioso albo castaneo- 

 tincto supra umbilicum modicum simplicem profundum circum- 

 fluente, ad anfractum ultimum munita ; fauce incarnescente. 

 Operculum corneum. Axis 4J-5, lat. 4 poll. Hob. Puget 

 Sound. 



This certainly exceeds in size all other species yet discovered. 

 It is allied to N. heros, some specimens of which occasionally 

 approach it in size. It is however less globular, and distinguish- 

 ed by the remarkable constriction near the suture. Specimens 

 were brought from the mouth of the Columbia, by Lewis and 

 Clarke, and have been designated by the above name. 



Natica caurina. Testa parva, solida, levigata, globoso-ellip- 

 soidea, albida, epidermide tenui stramineo induta, vix perforata : 

 spira obtusa, erosa, anfr. 44-, ultimo sub-tabulata, antice sub- 

 contracta ; apertura parva, semilunaris ; columella recta, postice 

 callo copioso albo induta. Axis 4-, diam. f poll. Hab. Straits of 

 De Fuca. 



Nearly the same as N. i?npervia, Phil, from Cape Horn, which 

 has a very depressed spire, and its umbilic closed by a semicir- 

 cular callus. Its form and color is like N. immaculata, Tott., 

 though it is much larger. It is more solid and less globular than 

 N. Grcenlandica. 



Natica soluta. Testa parva, globosa, sordide alba, striis 

 tenuissimis cincta : spira anfr. 5 ventricosis, superne sub-tabula- 

 tis ; sutura profundissima ; apertura semilunaris, angulo postico 

 callo firmato ; labio acuto, tenui, ad basim incrassato, subeffuso : 

 columella recta, callosa, post umbilicum parvum profundum dila- 

 tata. Diam. ^ poll. 



A small, nearly globular shell, allied to N. horeaJis, Gray, and 

 N. globosa. King, but distinguished by its deep-channeled suture. 



