382 PROCEEDINGS OF THE ACADEMY OF [1900. 



a'. Operculum thickened outside by conspicuous concentric or 



oblique laminae, thin in the middle (Metalycceus n. sect.). 



b. Operculum with blackish concentric laminae. Shell 



openly umbilicate, the umbilicus less than one-third 



the diameter of shell; whorls 3J, the post-nepionic 



spirally striate, the last half of the last swollen and 



straightened, more finely rib-striate, then contracted, 



nearly smooth beyond the contraction. Alt. 2.6, 



diam. 4, umbilicus 1J mm. Hakone Mountains. 



A. melanopoma n. sp. 



b' '. Operculum with raised oblique laminae around the edge 

 of the outer face, like a single coil of tarred rope ; a 

 pit in the middle. Shell with the general shape of 

 A. japonicus, the width of umbilicus one-third that of 

 the shell ; whorls 3 J, the post-nepionic one not striated 

 spirally, all but the nepionic finely rib-striate, the last 

 moderately swollen and then somewhat contracted, 

 smooth or nearly so beyond the constriction. Alt. 2.7, 

 diam. 4.7, umbilicus 1.5 mm. Kioto. 



A. hirasei n. sp. 



Full descriptions have been prepared to be published as soon as 

 the necessary figures illustrating them can be drawn. 



Diplommatina pusilla var. omiensis n. var. 



Smaller than D. pusilla, and more closely costulate, the inter- 

 vals between the riblets smooth. Alt. 1.9, diam. 1 mm. 



Ibuki, prov. Omi, Japan (Y. Hirase). 



In the form I have identified as D. pusilla, the riblets are more 

 spaced, about 12 to a millimeter, on the circumference of the last 

 two whorls, and the intervals are seen to be densely striated spirally 

 on the penultimate whorl, when viewed under a high magnification. 



In var. omiensis there are about 18 riblets in the space of one 

 millimeter, and the interstices look smooth under the same lens. 

 The form is much alike in the two species, but D. pusilla is a 

 trifle larger, a specimen measuring alt. 2.2, diam. 1.1 mm. Both 

 are sinistral forms. D. pusilla was collected by Prof, von Mar- 

 tens at Uweno, in the immediate vicinity of Tokyo. 



Macrochlamys micrograpta n. sp. 



Shell narrowly umbilicate, the width of umbilicus contained 

 about eighteen times in the diameter of the shell, depressed, glossy, 

 pale corneous brown, adults a little whitish around the umbilicus, 

 subtransparent, the earlier whorls visible through the base. Sculp- 



