624 PROCEEDINGS OF THE ACADEMY OF [Sept., 



the last rounded below. Constriction slight, immediately in front 

 of the upper insertion of the outer lip. Aperture subcircular, the peris- 

 tome thin and reflexed, a little thickened within. Columellar tooth 

 hardly visible in a front view, stronger Vithin. Parietal callous exten- 

 sive. Palatal plica long, partly under the callous, partly projecting 

 beyond it. 



Length 3.7, diam. 1.7 mm. 



Miyakojima, Riukiu. Types No. 87,655, A. N. S. P., from No. 1,299 

 of Mr. Hirase's collection. 



This is the largest Sinica of the Riukiu Islands which we have yet 

 obtained. The columellar tooth is very small in a front view. 

 Diplommatina vespa n. sp. 



Shell oblong, the upper third conic, the rest subcylindric ; dull red 

 or ashy brown. Sculptured with delicate rib-strise which are fine and 

 close on the cylindric portion of the shell, much more widely spaced 

 upon the conic spire, the first 1J whorls smooth. Whorls 8 to 8J, very 

 convex. The penultimate whorl abruptly contracts in front or on the 

 left side and continues narrow to the end, the last whorl being of nor- 

 mal proportions and very convex throughout. The aperture is sub- 

 circular, the lip broadly expanded and reflexed. The columellar la- 

 mella is rather small at the mouth, but larger inside. It ascends nearly 

 two whorls, to the constriction, where there is also a rather small 

 palatal plica, but no parietal spiral lamella. 

 Length 3.9, diam. 1.8 mm. 

 Length 3.7, diam. 1.7 mm. 

 Length 3.5, diam. 1.7 mm. 



Miyakojima, Riukiu. Types No. 87,634, A. N. S. P., from No. 1,297 

 of Mr. Hirase's collection. 



The closing apparatus recedes much more deeply in this than in 

 other Japanese Diplommatinas, but it does not lie quite so far back as 

 in a Bornean group of which D. everetti Smith is typical, called Paradi- 

 ancta } and subordinated to the genus Diancta by von Mollendorff and 

 Kobelt, whose classification of the Diplommatinidce shows some strange 

 groupings for which no reason is apparent. The section Metadiancta 

 Mlldff., based upon a series of Diplommatinas from the northeastern 

 frontier of India, has also some similarity. These forms as described 

 by Godwin- Austin are characterized by the position of the constriction, 

 which is on the side, near the end of the penultimate whorl, behind the 

 peristome, as in D. later alis and kumejimana, described above, but 

 differing from them in the deficient internal armature. 



It seems that in various places forms of Diplommatina have inde- 



