CGELIAXIS. 337 



well developed ectocone, but no trace of an inner cusp. 

 Marginal teeth similar, the ectocone split on a few of the 

 outer ones. 



Soft anatomy otherwise unknown. Reproduction vivip- 

 arous. 



The snail burrows in sand among grass and bushes. 



Type C. layardi. Distribution, South Africa. (C&Uaadg, 

 hollow axis.) 



This monotypic genus stands isolated in the recent fauna, 

 but it seems to have distant relations with Tkomea, Pyrgina 

 and Cryptelasmus. 



The name Coeliaxis was originally based upon C. layardi 

 only, though in a later publication its authors enlarged the 

 definition to include C. exigua (P. Z. S., 1867, 907). The 

 efforts of Messrs. Ancey and Girard to displace Coeliaxis by 

 other generic names for C. layardi must therefore be viewed 

 as energy misdirected. 



C. exigua, which Adams and Angas described as a Cceliaxis, 

 belongs to the genus Coclocion Pils. (Manual, vol. xvi, p. 190). 

 It has been referred erroneously to the genus Perrieria. 



1. C. LAYARDI (Adams & Angas). PI. 49, figs. 11, 12, 13, 14. 



Shell narrowly umbilicate, tapering-cylindric below, the 

 upper half strongly tapering and attenuate, with slightly con- 

 cave outlines, the apex globose and a little enlarged, fre- 

 quently truncate in adult shells ; thin but rather strong, cor- 

 neous, rather glossy; sculptured with close, fine and thread- 

 like rib-striae, which are about as wide as their intervals, but 

 slightly oblique, and sometimes are more crowded on the last 

 whorl. Whorls 20-21 in perfect shells, only slightly convex, 

 the last rounded below, without trace of a basal carina. 

 Aperture slightly oblique, irregularly ovate. Peristome thin 

 or a little thickened, obtuse, slightly expanded, the columellar 

 margin dilated and reflexed. Columella vertical, slightly 

 concave, bearing a small fold below. Internal axis hollow, 

 tubular and straight, encircled below the middle of each 

 whorl by a cord-like spiral lamella which extends upwards 

 about 3y 2 whorls from the base. Adult shells have a lamella 



