208 PROCEEDINGS OF THE ACADEMY OF [Marcll, 



than twice the altitude, and nearly three times the diameter; 

 anterior end longer, tapering, rounded; posterior end slightly con- 

 vex, bluntly angular below; the beaks situated at about the pos- 

 terior two-fifths of the length. Surface glossy, sculptured with 

 slight growth-lines and exceedingly fine, subobsolete radial stria>, 

 angular posteriorly, the posterior area sculptured ivith strong, 

 ■smooth radial ribs narrower than their flat intervals and terminating 

 on the angle. Ligament very short and swollen. Interior white 

 with brown stains near the ends; posterior lateral tooth strong; 

 basal margin finely ])ut distinctly crenulated. 



Length 9, alt. 5.5, diam. 3.3 mm. 



Hirado, Hizen (Mr. Y. Hi rase). 



A small species belonging to the section Chion, chiefly distin- 

 guished by the strong sculpture of the posterior end. 



ANATINID^. 

 Anatina impura n. sp. 



Shell oblong, fragile, rather ventricose, widely gaping posteriorly, 

 but slightly so in front ; sculptured with low, irregular wrinkles, 

 and where unworn, with the usual granulation. White and pearly 

 above, where worn through the very thin porcellanous coat, cov- 

 ered at the margins with a dirty yellowish cuticle, which is more 

 persistent and lamellose on the posterior rostrum. Beaks at the 

 middle of the shell's length, not turned forward, contiguous, one 

 of them worn through, both slit as usual. Anterior end broadly 

 rounded; dorsal margin almost straight; posterior end narrow, the 

 margins hardly expanded; basal margin parallel with the upper 

 margin except posteriorly where it rises suddenly. Interior whitish, 

 slightly wrinkled, the chondrophore and buttress as usual. 



Length 38, alt. 20, diam. 15 mm. 



Kamakura, province of Sagami (types No. 68,536 and 70,812, 

 coll. A. N. S. P.). 



This species differs from A. japonica Lischke in the median posi- 

 tion of the beaks and different shape of the posterior end. Lischke 

 has figured two somewhat diverse forms under the head .4. 

 japonica. That represented in his figs. 9, 10, has been taken by 

 Mr. Hirase at Hirado, Hizen. Having before me all of the 

 species of Anatina credited to Japan, as well as most of the Phil- 

 ippine forms, I find myself unable to place the specimens described 

 above in any of the accepted species. A. kamakurana, of which 



