586 PAXILLUS. — CLAUSILIA. 



Genus pro specie unica, haud facili alii generi inserenda , con- 

 siitutum, a Cl. Auctoribus cum dubio Auriculidis adscriptura, 

 Heliceis ex testae characteribus magis congruum, quamobrem, 

 deficiente animalis cognitione, pro tempore locum iu vicinia 

 Clausiliae ei assignavi. 



1. P. adversus H. et A. Adams. 



T. sinistrorsa, breviter rimata, ovato-conica, tenuis, sub- 

 tiUssime striatula, cereo-hyalina; spira ventrosa, sursum conica, 

 acuta; anfr. 8 planiusculi, ultimus angustior, antice arcuatim 

 ascendens; columella basi Iransverse lamellata; apertura parum 

 obliqua, semiovalis; perist. expansum, margine utroque ad an- 

 fractum penultimum ascendente, columellari reflexo. — Long. 

 6, diam. 3 milL Apert. c. perist. SV^ mill. longa. (Coll. Nr. 1.) 

 Paxillus adversus H. et A. Adams in Ann. and Mag. 2 d. ser. 



VU. p. 63. 

 Habitat prope Singapore (Adams); in insula parva prope Ma- 

 lacca (Mus. Cuming.). 



Obs. Nura ad hocce genus forsan pertineat Balea peregrina Gould? 



XXIll. Clausilia Draparnaud. 



Genus characteribus fixis, in Monographia 1. p. XXV et 

 in Alhers Helic. p. 213 expositis, circumscriptum , numero 

 specierum notarum mirum in modum continue increscens. Quae 

 mihi innotuerunt, methodo antea adhibita simili in sectiones 

 sequentes dislribuam. 



Conspectus specierum. 

 I, Aufraclu ultimo longe soluto, descendente, aper- 



tura subcirculari §. I.Nr. 1—3. 



11. Anfractu ultimo vix solulo vel appresso. 

 A. Lunella nulla. 



a. Apertura basi rotundata. 



a. Dextrorsae §.2. — 4. 



p. sinistrorsae 



* sublaevigatae §. 3. — 5 — 33. 



** costulatae §.4.-34 — 47. 



lumella with a single prominent tooth-like plait; ouler lip with a double 

 peritreme, emarginate anteriorly ; umbilical region with a spiral elevated 

 ridge, terminating in a notch at the fore part of the aperture. (H. et A. 

 Adams I. c.) 



