THE NAUTILUS. 43 



Diplommatina okiensis n. sp. 



The lower half of the shell, comprising two whorls, is cylindric, 

 the upper half tapering in a rather long cone with straight sides. 

 Adult shells are generally red-brown, rarely whitish, but the young 

 are nearly white. There are nearly 7 moderately convex whorls, 

 the penultimate, seen from the back, being the largest. The last 

 whorl ascends in front, and has a strong, rather sharp ridge or col- 

 lar a short distance behind the peristome, and preceded by a rather 

 wide opaque whitish streak. The constriction is slight and median 

 in front. The whole shell, after the smooth apex, has a sculpture 

 of very fine, delicate, oblique, moderately close thread-striae. The 

 aperture is nearly circular, the parietal callus having a slightly 

 thickened edge, reaching up nearly to the suture. Peristome well 

 reflexed, usually very slightly angular at the foot of the columella. 

 Palatal plica very short, half covered by the parietal callus. Colu- 

 mellar tooth moderately strong, deeply placed, thin but rather high 

 within. Internal parietal lamella strongly developed. 



Length 4, diam. 2 mm. 



Nakamura, Oki. Types no. 95663 A. N. S. P., from no. 296 c 

 of Mr. Hirase's collection. 



This species differs from D. paxillus (Gredler) by its strongly 

 developed collar. It is closely related to the common Japanese D. 

 collarifera Schm. & Bttg., but that species has a much longer palatal 

 plica, a decidedly thicker and stronger columellar lamella inside, 

 and only a weak internal parietal lamella. 



Trishoplita cretacea pergranosa n. subsp. 



The shell is depressed-conic with obtusely subangular periphery, 

 thin, whitish corneous, with a broad brown band on the base, ex- 

 tending from just below the periphery nearly to the umbilicus, and 

 a narrow brown band above the periphery, ascending the spire above 

 the suture. The surface has a minute sculpture of fine, somewhat 

 waved or irregular strioe, which are minutely and very elegantly 

 granulose ; no distinct spiral lines. 



Alt. 8.3, diam. 13.3 mm.; whorls 5^. 



Nishinoshima, Oki. Types no. 95840 A. N. S. P., from no. 

 1575 of Mr. Hirase's collection. 



This snail, of which only 7 examples were taken, is most nearly 

 related to T. c. bipartita of Nagato province, which is less depressed, 



