﻿SOME NEW GASTROPODS — LOOSJES 541 



Tlie closing apparatus lies laterally. Principal plica less than a 

 half-whorl long. Lunella oblique, above contiguous to a short upper 

 palatal j^lica, below slightly curved inward. 



Sudiral plicae, fulcrum, and parallel lamella are developed as is 

 characterized in Zaptyx s. s. 



The clausilium (fig. 51, c) as usual in Zaptyx^ with the curvature 

 chiefly near the filament; the distal end is rounded and the clausilium 

 is deeply excised on the columellar side at the filament. 



The radula (fig. 51, d) has the dental formula ^-fH^-^Xca. 80; 

 basal i)lates of rhachidian teeth and laterals broad, nearly quad- 

 rangular. 



ISIeasuremcnis: Length, 8.6 to 11.7 mm. (average, 9.7 mm.) ; diam- 

 eter, 2.2 to 2.8 mm. (average, 2.5 mm.) ; aperture : height, 1.9 to 2.6 mm. 

 (average, 2.2 mm.) ; width, 1.4 to 1.9 mm. (average, 1.7 mm.). The 

 averages are taken from 106 specimens. The type measures : Lengtli, 

 10.8 mm.; diameter, 2.8 nun.; aperture : height, 2.6 mm.; width, 

 1.9 mm. 



The type (U.S.X.M. No. 488973) and two lots of paratypes 

 (U.S.N.M. Nos. 256581 and 485571) were collected on Calayan Island, 

 Babuyanes group, Luzon, Philippines. All were received from the 

 Philippine Bureau of Science. 



This species is the first zaptychoid form recorded from a locality 

 south of Formosa. There is no doubt that it must be placed in Pils- 

 bry's section Zaptyx s. s. (distributed throughout the Ryukyu Chain, 

 Bonin Islands, and Formosa), near species like sarissa Pilsbry and 

 nakanoshimana Pilsbry. It differs from these by its club-shaped ap- 

 pearance, by its larger diameter, by the striation being not only behind 

 the lip on the last whorl but extending to the whole shell, excluding 

 only the embryonic whorls, by the rather thin peristome, the inferior 

 lamella continued on the parietal wall, etc. 



It is named in honor of my wife, who is much interested in my 

 study and who is contributing to it by furnishing as complete a survey 

 as is possible of the literature on the Clausiliidae. 



ZAPTYX (ZAPTYX) REHDERI, new species 

 FlGTJKE 52 



Shell of medium size, sinistral, club-shaped, the spire thick with 

 nearly straight lateral outlines, slowly and regularly tapering into the 

 broad obtuse apex. Sometimes the early whorls may be somewhat in 

 the shape of a staircase; thin, not transparent, grayish white, rather 

 dull. 



Whorls 81/2 to 10, the first 5 rather convex, the lower ones nearly 

 flat; faintly but densely striatulate, nearly 200 riblets on the penulti- 

 mate whorl, nearly smooth to the naked eye, sculpture slightly coarser 

 on the last whorl ; protoconch consisting of nearly 21/2 smooth whorls. 



