1902.] NATURAL SCIENCES OF PHILADELPHIA. 529 



Clausilia sieboldi Pfr. 



C. sieboldtii Pfr., Proc. Zool. Soc., 1848, p. Ill; Monographia Hel- 

 Viv., II, p. 165; Conchylien Cabinet, Clausilia, p. 100, PI. 11, figs. 



O. sieboldi Pfr., Monogr., VIII, p. 520. Kobelt, Fauna inoll. extra- 

 mar. Jap., p. 73, PI. 9, fig. 1. 



A species collected by Siebold, and described by Pfeiffer as 

 corneous -brown, with 10 whorls, a deep, arcuate lunella, visible 

 outside through the shell, and one moderate palatal plica. The 

 type measures 1 8 mm. long, 4 wide in the middle. 



Kobelt described and figured specimens taken by Dr. Rein at 

 Amakusa, and between Hiugo and Bugo (IJungo ?). He gives 

 the color as " dunkel hornbraun." " Die Principalfalte ist klein, 

 haufig gar nicht zu erkennen, die Mondfalte ist klein oder breit, 

 fast gerade, von der Principalfalte getrennt, und schicht unten 

 einen Ast nach hinten ; die Gaumenfalten fehlen oder es ist eine 

 ganz kleine vorhanden, welche mit der Mondfalte zusammenhangt. ' ' 



The relation of this form to the next is a matter for further 

 investigation, with more material than is at present available. 



Clausilia sieboldi var. diptyx nov. PL XXVIII, figs. 19, 20, 21. 



Shell fusiform or turreted, the greatest width being either near 

 the middle or at the last whorl ; the spire rapidly tapering above to 

 a rather small, acute apex, the outlines of the terminal portion 

 straight. Dark purple-brown, fading to pale or yellowish -brown 

 above. Surface glossy, sculptured with strong, close rib-striae, 

 narrower than their intervals. Whorls 9^, convex, the last some- 

 what flattened laterally, convex beneath, showing a pale or yellow- 

 ish curved streak in the position of the lunella. Aperture ovate, 

 dark within ; peristome white, thickened within, rather widely 

 reflexed, continuous, a little excavated at the sinulus. Superior 

 lamella rather small, thin, and short, not reaching to the lip -edge; 

 widely separated from the spiral lamella, which is a half whorl 

 long, penetrating to the middle of the ventral side. Inferior 

 lamella subhorizontal, thin, not extending upon the expanded lip, 

 ascending in a wide spiral within, penetrating as deeply as the 

 superior lamella. Subcolumellar lamella very deeply immersed. 

 Principal plica about a third of a whorl long, latero -dorsal. Upper 

 and lower palatal plicae rather short, subparallel, the upper one 

 curved ; they are connected by a very low lunella, scarcely notice- 

 34 



