586 PROCEEDINGS OF THE ACADEMY OF [DeC. 



NEW LAND MOLLUSCA OF THE JAPANESE EMPIRE. 

 BY H. A. PILSBRY AND Y. HIRASE. 



The present contribution includes species from the main island of 

 Japan, the Bonin Islands, Ryukyu Islands and Formosa. Recent 

 explorations in the Tokara Group (small volcanic islets between 

 Oshima and Yakushima) have filled a gap in our knowledge of the land 

 snails of the northeastern islands of the Ryukyu Curve, the Clau- 

 siliidce and operculate shells being especially interesting. 



Spiropoma japonicum tsushimanum n. subsp. 



The spire is slightly higher than in japonicum and the last whorl 

 descends more to the aperture. The cuticle is extremely finely and 

 densely striate, duller and darker than in japonicum; finally, the col- 

 umellar margin of the peristome is retracted more. 



Alt. 8, diam. 14.2 nam. 

 " 6.1, " 11.7 '' 



Izuhara, Tsushima. Types No. 95762 A. N. S. P., from No. 1447a 

 of Mr. Hirase's collection. 



The several species and local forms of Spiropoma are only very 

 slightly differentiated, and while the races of Tsushima, Quelpart, etc., 

 have a certain individuality appreciable to the eye, their differences 

 are of no great importance. The generic type seems to be very con- 

 servative and inflexible. 

 Alycaeus tsushimanus n. sp. 



The shell is quite depressed, otherwise shaped as usual in the sub- 

 genus Chamalycceus; very pale reddish-brown or whitish. Spire low, 

 convex, the apex projecting a little, brown. Whorls 3^, the first 1^ 

 smooth, the rest sculptured with extremely delicate, close thread- 

 striae; just before the constriction of the neck the striation is dis- 

 tinctly stronger, and on the neck it is more or less obsolete. Later 

 part of the last whorl is moderately swollen, then contracted. Beyond 

 the contraction the neck is swollen in the middle, then descends a little 

 to the aperture. The sutural "tube" is rather long, and very closely 

 appressed, as if partially melted into the suture. The aperture is very 

 oblique, circular. The peristome is strongly expanded and refiexed, 



