182 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VrOL. 38. 



I 



aperture, which stands forward about I mm. The neck is deeply 

 grooved above the suture. The aperl lire is slightly oblique, rounded- 

 ovate, with continuous, reflected, pale brownish peristome. The 

 superior lamella is acute, concave on the left side, continuous with the 

 spiral lamella, which is low and short, running inward to 

 a dorsal position. The inferior lamella is immersed, 

 barely visible in a front view. It ascends in a Ion"; 

 sigmoid curve, and is somewhat thickened within. 

 The subcolumellar lamella is wholly immersed. The 

 principal plica is high, dorsal, and less than a half 

 whorl long. The lamella is low and lunate. 



Length 20.1, diameter .'!.!) mm. ; longest axis aperture 

 3.8, width 3 mm. The clausilium is evenly curved, 

 slightly twisted spirally, the distal half tapering to the 

 obtuse, thickened apex. 



Type.—U. S. Nat. Mus. No. 209272. 

 By its sculpture this species resembles ('. pilsbryi 

 Sykes and C. chacaensis Lubomirski, but in those the 

 stria 1 are more distinctly interrupted and liner. It 

 differs from both by its short aperture, proportioned 

 more as in 0. epitonium; both of the other species 

 named having the aperture conspicuously lengthened. 

 The distinct attenuation of the earlier whorls is a further distinct i\ i 

 feature of the new form. 



The latest list of South American Clausilise ° enumerates 37 species. 

 A few species described since that time, together with some omitted. 

 brings the number up to about 45 species, exclusive of those Clausi- 

 liidae belonging to the genus Temesa. (IT. A. P.) 





Fig. I. Clauselia 



(NENIA) PAMPA- 

 SENSIS. 



a E. K. Sykes, Journ. Malar., vol. .">, L896, {>. 57. 



