116 COLUMBELLA. 



3. Ako STOMA. The aperture turned up towards the spire. 



Fig. 271, 272. 



4. Streptaxis. "Whorls excentric. Pig. 269, 270. 



5. Bui/iNTJS. Oval ; aperture entire, including Bulimulus, 



Balea, Cionella, Azeca. Pig. 282 to 285, 289, 290, 296. 



6. AcHATiKA. A notch terminating the columella. Pig. 286 



to 288. 



7. Pupa. Cylindrical ; including Vertigo, Alcea, &c. Pig. 



291 to 293. 



8. Clatjsilia. Cylindrical, with a clausium. Pig. 295. 

 Obs. The above are united in the system of De Perrusac 



under the generic name Helix, and divided into sub-genera 

 as explained under that word. 



The next section, included in the family Auriculacea, Bl., con- 

 tains the genera Auricula, Chilina, Carychium, Marinula, 

 Scarabaeus, and Partula. Pig. 297 to 302. 



The third section contains the following genera of land shells 

 with opercula. 



1. Ctclostoma. Aperture round ; operculum spiral. Pig. 



303, 304. 



2. Nematiiea. Last whorl contracted ; operculum spiral. 



Pig. 305. . i 



3. PIelicina. Aperture semi-lunar or angulated ; operculum 



concentric. Pig. 306, 307. 



4. PupiNA. Shell polished ; operculum concentric ; aperture 



round. Pig. 



5. Strophostoma. Aperture turned up towards the spire, 



like Anostoma, but said to have an operculum. Only 



known fossil. Pig. 97. 

 COLTJMBELLA. Lamarck, 1801. (Columba, a dove.) Fam. 

 Columellata, Lam. — Descr. Thick, oval, or angular; with short 

 spire, and long narrow aperture, contracted in the centre, and 

 terminating in a short canal ; outer lip thickened and dentated ; 

 inner lip irregularly crenated. Epidermis thin, brown. Oper- 

 cvxlum very small, horny. — Obs. Those species of Mitra, which 

 resemble Columbella in shape, may easily be distinguished by 



