520 PROCEEDINGS OF THE ACADEMY OP [AugUSt, 



to those above it, in the present species that plica stands obliquely, 

 like a lunella, though not quite near enough to the vertical posi- 

 tion to be called a lunella. In C. addlsoni I have shown a lunella 

 to exist, but in combination with a normally developed lower 

 palatal plica. 0. acldisoni is distinguished externally from 

 G. plagioptyx by its stronger rib-striation. C. plagioptyx is a more 

 solid shell than either hrevior or addisoni. 



The clausilium had fallen out of the two specimens of this species 

 sent by Mr. Hirase. 



C hrevior, as I stated in a former paper, is not known from south 

 or southwest of middle Hondo. It is a species of the region about 

 Tokyo. At this time we have no Stereophcedusa of the hrevior 

 type in southwestern Hondo, Awaji, Shikoku or northern Kyushu. 

 C. addisoni is found in Higo and Satsuma, in southern, and 

 C. plagioptyx in Hizen, in western Kyushu. 

 Clausilia stereoma var. hexaptyx nov. 



Shell somewhat larger than stereoma, and thinner, much less 

 strong ; dark reddish-brown or pale straw-yellow ; palatal plicae six, 

 the upper and lower long, curved, the intermediate ones strong 

 (as in 3Iegaloph(edusa) , though more or less unequal. 



Length 24.4, diam. 7 mm. 



Length 24, diam. 7.1 mm. 



Length 22.2, diam. 6.8 mai. 



Length 23, diam. 6.5 mm. 



Yaku-jima, Osumi. Types No. 83,302, A. N. S. P., from 

 No. 670a of Mr. Hirase' s collection. 



Differs from the forms of stereoma already known by its strong 

 Megalophsedusoid palatal folds. The clausilium is like that of 

 C. stereoma. To what extent the forms of stereoma intergrade 

 remains to be determined. 

 Clausilia oostoma Mollendorff. PI. XXVII, figs. 15, 16, 17, 18. 



C. oostoma Mlldff., Journ. Asiat. See. Bengal, LI, pt. 2, p. 4, PI. I, 



fig. 3 (1882). Pilsbry, Proc. Acad. Nat. «ci. Pliila., 19U0, p. 607. 



0. japonica var. surugm Pils., Proc. Acad. Nat. Sci. Phila., 19U0, p. 



447, PI. 14, fig. 4. 

 C. eurystoma var. brachyptycMa Mlldff., Nacliriclitsbl. d. d. inalak. 

 Ges., 1901, p. 41. 



Shell rather .solid, club-shaped, the upper three-fifths of the 

 length tapering and somewhat attenuated, the outlines gently con- 

 cave above ; apex rather large ; white under a yellow cuticle. 



