504 ' - PROCEEDINGS OF THE ACADEMY OF [DeC, 



shown in the profile view. In some specimens it has a concavity in 

 the inner face corresponding to the external callus. The main cur- 

 vature of the clausilium is not far from the origin of the filament; 

 elsewhere it is nearly straight in profile view. 



In specimens from Ikejijima, Oshima, the external callosity referred 

 to is weak. In those from Koniya, Oshima, the clausilium is typical. 

 The shells from this place are more delicate, thinner than the types of 

 C. munus {muniis, a gift). 

 Clausilia diacoptyx n. sp. PI. XXXIII, figs. 13-19. 



Shell fusiform, the apex rather obtuse, whorls 8 to 9, moderately 

 convex, the last tapering downwards. Surface glossy, smooth, 

 faintly striatiilate, the last whorl rib-striate for a short distance 

 behind the outer lip. Pale greenish corneous, somewhat transparent. 

 Aperture ovate, the lip well reflexed and thick. Superior lamella 

 marginal, continuous with the spiral lamella, which is high in the 

 lateral region, and extends inward to a point above the superior lamella. 

 Inferior lamella deeply receding, straightened and obliquely ascending 

 within, shorter than the spiral lamella, or equal to it. Subcolumellar 

 lamella strongly emerging to the lip-edge, a groove with raised margins 

 on each side of it. Principal plica somewhat more than a half whorl 

 long, dorsal and lateral, approaching the lip. Upper palatal plica 

 consisting of two portions, the inner portion short, across the top of 

 the straight, lateral lunella, the other portion widely separated from 

 it, dorsal, visible in the mouth, long, and diverging forward a little 

 from the principal plica. 



I.ength 10, diam. 2.3 mm. 

 8.8 " 2.3 " 



The clausilium (PI. XXXIIl, figs. 15, 16, 17) is rather long with 

 snbparallel margins, the columellar margin aljrupth^ excised above, then 

 straight, and near the apex strongly curved towards the palatal margin. 

 The apex is curved toward the palatal margin and then outward in an 

 acute point, separated from the palatal side by a rather deep excision, 

 which is scarcely apparent in a front view, ])ut is conspicuous in a 

 profile view from the palatal side. The palatal margin is thick and 

 sliglitly arched. 



Sammaipo, Taiwan (Formosa). Types No. 89,896, A. N. S. P., 

 from No. 1,430 of Mr. Hirase's collection. 



This species is probably related to C. uraniscoptyx Schm. and Bttg., 

 from Bankimtsong, Formosa, but unfortunately the clausilium of 

 that species has not been described. The present form differs from 



