1902.] NATURAL SCIENCES OF PHILADELPHIA. 29 



very widely spaced on the spire, rapidly becoming finer at the 

 beginning of the penultimate whorl, which is very finely and closely 

 striate ; last whorl contracted, similarly sculptured but with the strise 

 partially effaced, ascending as usual. Aperture somewhat oblique, 

 subcircular, the peristome expanded and reflexed, but not doubled 

 and with no rib behind it. The columellar tooth is rather small, 

 and deeply placed. No palatal fold is visible through the shell. 

 Length 3, diam. 1.5 mm. 



Nachi, Kii. Types No. 82,652, Coll. A. N. S. P., from No. 

 836a of Mr. Hirase's collection. 



A very distinct species, like D. kobelti in the long spire, but in 

 D pudica the cone is more slender above. The disparity in sculp- 

 ture between the whorls of the cone and the last two is unusually 

 marked. The color of fresh, unworn shells is deeper than in the 

 other species of Nippon known to me. 



Mandarina exoptata var. obtusa nov. 



More depressed than the typical form, and merely angular at the 

 periphery ; whorls 4J-. 



Alt. 1 3, diam. 22 J mm. 



Hahajima, No. 845 of Mr. Hirase's collection. 



Mandarina mandarina var hahajimana nov. 



Shell small, thinner than typical mandarina, pale yellowish; 

 uniform or with a pale reddish band above, another below the 

 periphery. Whorls 4J, the last slightly angular in front, soon 

 becoming rounded at the periphery. Surface very densely engraved 

 with clear-cut, minutely crimped spiral strise, obsolete immediately 

 around the axis. 



Alt. 13J, diam. 18 J mm. 



Sekimon-zan, Hahajima (Mr. S. Yoshiwara) ; Hahajima (Mr. 

 Y. Hirase). 



Genus HIRASEA Pilsbry. 



This group has been modified to fill many places in the Ogasa- 

 waran snail fauna. Six species have already been found on Haha- 

 jima alone, and one on Chichijima. Those known from the former 

 island may be determined by the following key : 



