370 Mr. Jeffreys on the Testaceous Pneumonobranchous 



versim substriata. Anfractus 6. Apertura oblonga, 

 angustior, plicis 2 columellaribus munita : peristomio 

 simplici. 



Long. 0.175.— Diam. 0.065. 



Voluta alba. Mont. Test. Brit. p. 235 ? (not of the 

 Suppl.) Turton's Conch. Diet. 



Not uncommon among the rejectamenta of streams, near 

 their communication with the sea. 



The Voluta triplicata of British authors (if a true Auri- 

 cula) has as yet only been found in Guernsey ; and is there- 

 fore not admissible into the present catalogue. 



Familia III. LIMN^AD^E. Leach. 



Tentaculis compressis, triangularibus. 



Divisio I. Testa cochleceformis. 



§ Test^ turrita. 



13. Limneus. 



14. Physa. 



Tentaculis compressis, subulatis. 



|§ Test^ discoided. 



15. Planorbis. 



Divisio II. Testa patella for mis. 



16. Ancylus. 



Genus XIII. LIMNEUS. Drop. 



Animal tentaculis brevibus. Sustentaculum latum, antic^ bifidum. 

 Testa ovato-oblonga, sen elongata, interdiim subconica. Apertura 



ovato-oblonga, ad basin effusa : peristomio simplici, po- 



stic^ subreflexo : columella revolutd. 



All the inhabitants of this genus may be truly termed 



amphibious, 



