NATICA. 35 



N. LARVATA, Canefri. PI. 23, fig. 64. 



Smooth, very minutelj- decussately striate, subplicate at the 

 suture ; bluish white, with two iudistiuct chestnut bands ; umbil- 

 icus entirely' filled b}' a lieavj^ white columellar callus ; aperture 

 chestnut-colored. Length, 18 mill. 



Hah. unknoion. 



The operculum has not been observed, and the s^'stematic 

 position of the species is uncertain. 



Section Lunatia, Gray, 1841. 

 N. Lewisii, Gould. PL 13, figs. 11, 12 ; PI. 9, fig. 70. 



Conical globose, obsoletelj'' spirally striate, j^ellowish white or 

 brownish white ; whorls obliquely sloping above with, in old 

 specimens, an obtuse angle on the shoulder, defined by a slight 

 concave constriction above and below it ; interior chocolate- 

 white ; umbilicus narrow and deep,with a tougue-shajoed, chocolate- 

 tinged callus extended partly over it from above. 



Length, 3-5 inches. 



California^ Oregon, etc., Jajjan. 



The largest species of the genus. Small specimens are regu- 

 larly rounded on the upper portion of the whorls ; it is only with 

 advancing age that the constriction gradually becomes more 

 apparent. The species is generally known as N. herculea, Mid- 

 dendorff", but that name was published two years subsequently. 

 JSf. Reiniana.^ Dunker (fig. 12), a Japanese species, is surely a 

 synon3an ; and N. algida, Gould (fig. 70) is the 3'oung. 



N. HEROS, Say. PI. 13, figs. 13, 10 ; PI. 14, figs. 19, 20. 



Yellowish, or brownish white, with obsolete waved minute 



spiral striae, interior flesh-color, columella only slightl}' callously 



thickened, flesh-color, scarcely contracting the narrow, deep 



umbilicus. Length, 3-4*5 inches. 



Maine to Neiv Jersey. 



N. heros is a northern species, graduall}' replaced southwards 



by N. duplicata. The latter has been confounded with it by 



British authors. Like AL duplicata, it preys extensively on 



other mollusks ; on the New Jersey coast Mactra solidisaivia is 



its usual victim, being grasped in the voluminous foot of the 



