30 NATICA. 



whorls chestnut-color, with a narrow white sutural band, a white 

 peripheral band, and the lower part of the body-whorl also white. 



Length, 1'5 inches. Hong Kong, Singapore, Mauritius. 



It is N.fasciata, Martyn, N. leucozonias, Gmel. 



Var. SPADICEA, Gmelin. Fig. 63. 



The coloring lighter and more diffused, often varying in 

 intensity in obsolete bands and spiral lines, the sutural white 

 band wider. 

 Var. FORSKALI, Chernn. 



On p. 20 I have treated this as a distinct species ; it has been 

 regarded by some conchologists as a variety of N. rufa in which 

 the coloring is interrupted by the growth-lines causing it to 

 form longitudinal oblique stripes instead of being diffused over 

 the entire surface. It is very possible that it has been correctly 

 placed here. 



N. HELVACEA, Lam. PL 9, fig. 64. 



Whorls somewhat slanting above, then more convex ; umbili- 

 cus deep, contracted above by the callus ; a diffused white baud 

 at the suture, then a broad diluted chestnut baud extending to 

 below the periphery, base white ; on the chestnut space, at the 

 periphery is a narrow white band, above it generally another, 

 obsolete. Length, 1-5 inches. Singapore. 



Perhaps only a variety of the preceding species, which it 

 decidedly resembles in coloration, differing mainly in the 

 sloping conical form, and narrower umbilicus with the entering 

 callus barely indicated. It is usually called N. globosa, Chemn., 

 but this is only a portion of the descriptive phrase used by that 

 author to designate the species. It is N. spadicea, var. ft, of 

 Dillw., and N. pallens, Phil. 



N. CLAUSA, Brod. and Sowb. PL 9, figs. 05, 67-69, 73. 



Shell globose, whitish or yellowish white, spire often tinged 

 livid, umbilicus entirely covered and closed by a callus. 

 Length, 1*25-2 inches. 



Arctic Seas circumboreal, N. Japan, Alaska, 



Melville IsL, Greenland to Massachusetts, 



Arctic Europe, Off Coast of Portugal 



(nearly 1000 fms.). 



