THE NAUTILUS. 33 



tractive below the suture, and very faint, fine spiral striae. Whorls 

 5^, the earlier ones worn, blue, scarcely convex, the last 2 or 2^ 

 flattened below the suture, then convex ; last whorl is somewhat con- 

 cave below the suture, elsewhere well rounded. The aperture is only 

 slightly oblique, half-circular, brown inside, witli a white band within 

 the acute lip, which is built forward near the upper insertion. The 

 columella is white, rather thick, with a very weak, low lobe partially 

 filling the umbilicus, above which a lobe projects angularly forward 

 and is appressed to the shell wall. The parietal wall is almost nude 

 in the middle but has a heavy white callus in and below the posterior 

 angle of the aperture. The umbilicus is narrow. 



Alt. 41.5, diam. 35.5 mm. 



The operculum is thin, rich chestnut- colored, somewhat concave 

 outside in dry specimens, with the nucleus near the columellar n)ar- 

 gin, as usual. It seems to comprise about 2^ whorls. 



Akkeshi, Kushiro. Cotypes no. 97973 A. N, S. P., and no. 1706 

 of Mr. Hirase's collection. 



This form belongs to the subgenus Lunatia. It differs from the 

 young stage of P. lewisii by the shape and uniform whiteness of the 

 columellar callus (pila, a ball). 



Polinices hathyraphe n. sp. 



The shell is small, openly umbilicate, globose, white under a thin 

 light yellow cuticle. The spire is very short Hnd low, the early 

 whorls white and worn. The suture is deeply impressed, and in 

 the last whorl conspicuously channelled. The surface is sliining, 

 marked with fine growth-lines and minute spiral striae, which are 

 strongest around the umbilicus. There are 3^ convex whorls, the 

 last very large, flattened and depressed at the suture, elsewhere con- 

 vex. The umbilicus is large and open. Aperture very oblique, 

 half round, white within. Outer and basal lips are thin and sharp. 

 Columella concave, obtuse and simple below, but above, in the um- 

 bilical region, it dilates, forming a small, slightly thickened lobe, to 

 some extent arching over the umbilicus, and adnate above. The 

 parietal wall is very short, white, and heavily calloused throughout. 



Length 6, diam. 6.5 mm.; longest axis of the aperture 5.3 mm. 



Fiikura, Awaji, Cotypes no 97i>74 A. N. 8. P., and no 1676 of 

 Mr. Hirase's colhction. 



