THE NAUTILUS. 5 



sidered a distinct species, and it may prove to be so ; but it belongs to 

 a group of forms which may for the present be ranked as subspecies 

 of E. mimula, and including the following: 



E. mimula Pils. 



E. mimula trachyderma Pils. & Glide. (E. aperta trachyderma, 

 Proc. A. N. S., 1901, 614). 



E. mimula mikuriyensis Pils. (E. aperta mikuriyensis, Naut., 

 xvi, 45). 



E. mimula goniosoma Pils. & Hir. 



Punctum elachisturn n. sp. 



Shell umbilicate, depressed, brown, the first whorl whitish. 

 Whorls 2|, the last one sculptured with rather widely spaced lamellae 

 and close spiral strise in the intervals, the spire nearly smooth. The 

 whorls enlarge rapidly, and the last one is somewhat compressed be- 

 low the periphery, which is rounded. The aperture is large, oblique 

 and rounded, about one-fourth of the circle excised by the preceding 

 whorls. Alt. 7, diam. 1.2 mm. 



Yanagawa, Chikugo. Types no. 86492 A. N. S. P., from no 

 1159 of Mr. Hirase's collection. 



There are fewer whorls than in P. leptum, which is also a little 

 larger, and judging from the figures, more densely lamellose. 



Punctum apertiirn n. sp. 



Shell broadly umbilicate, depressed, thin, brownish-corneous, 

 sculptured with delicate, thread-like riblets, in large part cuticular. 

 Whorls 3, convex, parted by an impressed suture. Aperture ob- 

 lique, rounded, slightly more than one-fourth of the circle excised by 

 the preceding whorl ; peristome thin and simple. Alt. 7, diam. 2mm. 



Nemuro, Nemuro. Types no. 86490 A. N. S. P., from no. 1156 

 of Mr. Hirase's collection. 



This little snail from the northeastern province of Yesso, is dis- 

 tinguished by its depressed form and wide, shallow umbilicus. 



Zonitoides chishimanus n. sp. 



Shell openly umbilicate, whitish-corneous, thin ; closely and deli- 

 cately rib-striate, densely and finely striate spirally between the 

 lamella?. Spire convex. Whorls nearly 3^, convex, slowly increas- 

 ing, the last rounded peripherally and below. Aperture quite ob- 



