THE NAUTILUS. 127 



appears as a very good specie?. Side by side with New England 

 specimens there is practically no difference except in the thickness of 

 the shell. That counts for nothing in determining a species. For 

 example take New England Purpura lapillus and see the thin paper 

 shell from one region and the heavy robust one from another locality. 

 Add now O. bisuturalis and trifida. What determines the species? 

 Revolving lines are interesting marks, but we have no standard, 

 variety is everywhere. I take a few examples from my own cabinet ; 

 for convenience I will number the grooves from suture to the 

 shoulder on the last whorl 1, 2, 3, 4. Here are some results : 



Branford specimens vary thus: 1000-1004-1200-1204-1234. 



Woods Holl: 1000-1004-1200-1204. 



Sheepscote River, Maine: 0000-1000-1200-1 234+. 



Prince Edwards Island: 1000-1234+. 



The plus sign means that additional lines appear, usually less con- 

 spicuous, between the more usual grooves. Perhaps this list may be 

 altered, but I let it stand. There is so much difference, some 

 deeply grooved while others are faintly marked. The above is the 

 result of using a good lens and strong light across the lines. It looks 

 as if these three species would have to shake hands and be one. I 

 may add that the specimens from Maine and Prince Edward's Island 

 are more deeply marked than the shells from southern New England. 



NOTICES OF NEW JAPANESE LAND SNAILS. 



BY HENRY A. PILSBRY. 



Helicina osumiensis n. sp. 



Shell depressed, convex above and below, bluntly angular at the 

 periphery, rather thin, red ; striatulate, and under a strong lens 

 showing fine spiral striag. Spire low-conic, the apex obtuse ; whorls 

 4, scarcely convex, the last somewhat flattened above the peripheral 

 angle. Aperture oblique, irregularly semicircular, the peristome 

 very slightly expanded, upper margin nearly straight ; a moderately 

 thick, smooth callus on the base. Alt. 2i, diam. 4 mm. 



Kikai, province Osumi, southern Kiusiu (Mr. Y. Hirase). 



Closely related to H, verecunda Gould (Otia Conchologia, p. 105) 

 from the Loo Choo Islands, but much smaller, with the basal callus 

 smooth, not roughened or pitted as in that species. 



