206 PROCEEDINGS OF THE ACADEMY OF [Oct., 



A PECULIAR VENEZUELAN LAND SNAIL. 

 BY HENRY A. PILSBRY. 

 Xenodisciila venezuelensis n. gen. and sp. Fig. 1. 



The shell is minute, discoidal, being concave above and below, 

 whitish-transparent, glossy, with sculpture of spaced radial grooves 

 after the first half whorl. These grooves become closer near the 

 aperture, and in the largest and freshest specimens they are occupied 



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Fig. 1. — Xenodiscula venezuelensis. Three views of the shell, and aperture 



more enlarged. 



there by projecting riblets (which may be partly cuticular and de- 

 ciduous). There are not quite three whorls, rapidly increasing, 

 convex, most strongly so above. The aperture is oblique, wide, 

 of irregular shape. On the parietal wall there is a high, thin median, 

 emerging lamella, which penetrates only a short distance, and near 

 the columella there is an oblique, much smaller lamella. The outer 

 and lower margins of the lip are thickened within and toothed. On 

 the columella there is a small blunt tooth followed by a more taper- 

 ing one, with a low third prominence in fully adult shells. Within 

 the outer lip, above the periphery, there is a group of three small 

 teeth, the upper one largest,- the other two sometimes lacking, or 

 developed later. 



Alt. 0.55, diam. 1.6 mm. 



Cariaquita, Venezuela, S. Brown, Bond Venezuela Expedition, 

 1911. Type and paratypes, No. 105,209, A. N. S. P. 



All of the specimens are empty shells, obtained by sifting leaf 

 debris. The affinities of the species remain uncertain, as it is very 

 unlike any described form, but it doubtless belongs to a ,new genus, 

 which may provisionally be placed near Proserpinula or Volvidens, 

 both Antillean genera. 



In the type specimen there is a very minute lamella above the 

 parietal, lacking in the other examples. 



