﻿SOME NEW GASTROPODS — LOOSJES 543 



a half-whorl long. Limella oblique, slightly curved, above in connec- 

 tion with the middle of a short, but distinct upper palatal plica, below 

 touching a faint lower pahUal plica that extends mainly outward. 

 Below the ventral inward-curved horn of the lunella lies the end of the 

 subcolumellar lamella, 



BctAveen the principal plica and the suture there are two faint 

 sutural plicae, and between the lamella spiralis aiid suture we find the 

 fulcrum and parallel lamella as usual in Zaptyx s. s. 



Clausilium (fig, 52, d) with the curvature chiefly near the filament 

 and deeply excised there on the columellar side. Like the preceding 

 species the sides of the plate are nearly parallel. 



The type has 10 whorls and measures: Length, 19.5 mm.; diameter, 

 8,8 nun.; aperture: height, 3.6 nun.; width, 2.4 mm. One other para- 

 type (U.S.N.M. No. 485510) from the same lot has 8V2 whorls and 

 measures: Length, 16.7 mm.; diameter 3.0 mm.; aperture: height, 

 8.7 mm, ; width, 2.6 mm. 



The type (U.S.N.M. No. 488974) and paratype (U.S.N.M. No. 

 485510) were collected on Calayaii Island, Babuyanes group, Luzon, 

 by R. C. McGregor. 



There is no doubt that this species is closely allied to the preceding 

 one. It too belongs in the subgenus Zaptyx and is most closely related 

 to the section of that name. Some characters, hoAvever, make it diffi- 

 cult to place it in that section ; they are : its length (more than 14 mm. 

 long), the number of whorls (8^/2 to 10), the ventrolateral position of 

 the closing apparatus, and the presence of a /J)7^<?a palatalis inferior. 

 Including the lack of ribs on the whorls, these characteristics are the 

 principal differences from annae too. 



I propose for this new section, of which reluleri, is the type and only 

 representative at the moment, the name Prozaptyx. It is character- 

 ized by the above-mentioned differences from the section Zaptyx s. s. 



I dedicate this new species to Dr. H. A. Rehder, of the United States 

 National Museum, who introduced this species, among others, to me, 

 and who has always been ready to help my studies. 



When Pilsbry constructed his "Zaptychoid phylum" lie gathered the 

 forms out of Hemiphaedusa to which they belonged at that time. 

 Ehrmann's theory (1927), that the members of the genus Zaptyx 

 Pilsbrj' might be descendants of a now extinct hemiphaedusoid group 

 that might have lived in the southern part of Hondo, was modified in 

 several aspects b}' Kiiufel (1930), one point being that the highly 

 specialized zapt^-choid Phaedusinae, distributed over the very discon- 

 tinuous area of islands, south of the Japanese main island, had origi- 

 nated not once but many times from hemiphaedusoid ancestors. 

 Kaufel points out that specialization on the main island {Zaptychopsis 

 Ehrmann) from its very nature could not have proceeded as far as 

 on the smaller islands. Neither, of course, has the development on 



