1901.] NATURAL SCIENCES OF PHILADELPHIA. 469 



to C. Hwigeffordiana, from which it differs in being smaller and 

 more graceful, decidedly more attenuated above, with much 

 stronger striation. There is no trace of a lunella. It is from 

 Hokkaido Island, while C. Hungerfordiana is from southeastern 

 Hondo. Perhaps northern Hondo will supply specimens of inter- 

 mediate character. 



The shell figured is 10 mm. long. 



Group of C. euholostoma. 



Shell shorter than in normal Euphcedusce, the whorls reduced to 

 7-7^; aperture broad, squarish-oval, scarcely narrower above than 

 below; peristome continuous, the broadly arched parietal margin 

 in part adnate, though distinct. No superior lamella. Inferior 

 lamella strong; spiral lamella and principal plica very short; no 

 lunella; upper and lower palatal plicae developed. Clausilium 

 Euphiedusoid. 



The single species of this group approaches Reinia in contour, 

 but, like the preceding group, the superior lamella is obsolete and 

 the inferior lamella strong. 



Clausilia euholostoma Pils. PI. XXV, figs. 6, 7, 8. 



Pilsbry, Nautilus, XIV, p. 108 (January 1, 1901). 



Shell rimate, slenderly pupiform, brown, finely striate. Apex 

 rather acute; spire rapidly tapering above; whorls 7-7 , quite 

 convex, the last two forming much more than half the shell's 

 length, and of about equal diameter. Aperture of a broad, 

 squarish-oval form, scarcely narrower above than below; peristome 

 white, reflexed, continuous, the strong parietal margin arcuate and 

 in part adnate. Superior lamella wanting. Spiral lamella reduced 

 to a short plate deeply immersed, developed in a lateral position. 

 Inferior lamella appearing in a front view as a strong triangular 

 plate, strongly spiral within. Subcolumellar lamella very deeply 

 immersed. Principal plica reduced to a short fold, lateral in posi- 

 tion and about twice as long as the small upper and lower palatal 

 plicfe. No lunella. Clausilium very similar to that of C. comes,* 

 but the palatal margin is more straightened near the apex, and the 

 columellar margin is more strongly notched near the filament. 



Length 8.6, diam. 2.4 mm.; length of aperture 2.3 mm. 



Length 7.3, diam. 2.2 mm. ; length of aperture 2 mm. 



2 See these Proceedings for 1900, PI. XXV, figs. 35, 36. 



