NAT1CA. 37 



X. PATAGONICA, Phil. PI. 14, fig. 24 ; PL 21, fig. 12. 



Shell globose, solid, smooth, white, suture profound, umbilicus 

 narrow. Length, 1'4 inches. 



Straits of Magellan. 



N. globosa, King (unfigured), from the same locality, appears 

 to agree in description, except that it is said to be thin. Per- 

 haps X. Magellanica, Phil. (fig. 12), may also be referred here. 



X. ATROCYANEA, Phil. PL 14, fig. 21. 



Ovately globose, rather thin, bluish or bluish-white, with a 

 white band at the suture, and white also at the base ; umbilicus 

 narrow ; interior and columclla chocolate-colored. 



Length, 1*5 inches. 



Straits of Magellan. 



X. FORTUNEI, Reeve. PL 14, figs. 22, 23 ; PL 9, fig. 72 ; PL 21, 

 fig. 9, 



Conically globose, with elevated spire and well-marked suture, 

 umbilicus narrow, slightly contracted by callus above ; yellowish 

 white to brownish, interior tinged with chocolate. 



Length, 42 mill. 



China. 



Reeve's example was a young one (fig. 22), and resembles 

 Xatica tennis, Philippi (not Recluz), so closely (fig. 9), that I 

 am inclined to consider that shell also identical ; although it is 

 said to be as thin as paper, whilst Fortunei is of medium thick- 

 ness. The name tenuis was used at an earlier date by Recluz. 

 Perhaps N. gilva, Phil. (fig. 72), is identical ; if so, the name will 

 take precedence. 



X. PALLIDA, Brod. and Sowb. PL 14, figs. 27, 20, 28 ; PL 13, fig. 

 15; PL 9, figs. 76-78. 



Ovately globose, narrowly umbilicated, smooth, dirty white 

 under a yellowish brown thin epidermis. Length, 28 mill 



Arctic Seas circumboreal ; Maine, Massachusetts. 



N. borealis, Gray (fig. 76) ; N. alba, Loven ; N.pusilla, Gould, 

 Forbes and Hanley (not Say) (fig. 78) ; N. Grcenlandica, Beck 

 (fig. 35) ; N. lactea, Loven ; N. fo/Z&osa, Reeve, (fig. 77), probably 

 N. Beverlii, Leach ; N. Gouldii, Phil. (fig. 15) ; N. suturalis, 

 Gray (fig. 28); N. livida, Laskey ; N. caurina, Gould (fig. 26), 

 are synonyms. 



