61 



HELICID^E. 



HELICID^E. 



I. Sub-genus. Helicophanta, FeYussac. 



Peristome simple. 

 1st Group. Yttrinoidet, Fdr. (Ildix brevipcs, Ac.). 



Peristome thickened and subreflected. 



2nd Group. Veticuke, Fdr. (II. Cafra, Ac.). 



Jt ErolutaUe : Cochloldes. 



II. Sub-genus. CoMohydra, Fdr. (Succinea, Drap. ; Amphibulima, 

 Lam. ; Amphibulimus, Moutf.). 



(ft) Jnclut<e. 

 * Yolu.ta.tce: JJdicoidet. 



IIL Sub-genus. Hdicogena, FeY. (Helix, Linn.). 

 Columella solid and twisted. 



1st Group. Columellatce. 



a. Peristome simple. (Hdix naticoides, Ac.) 



8. Periatome reflected or thickened. (Helix Jamaiceneii, Ac.) 



Shell perforated. 



2nd Group. Perforates, Fdr. (Helix liyata, Ac.). 

 Shell umbilicated ; umbilicus entirely covered. 



a. Shell globulose or subtrochoid. 

 3rd Group. Acavi (Helix agpersa, Ac.). 



Shell imperferate. 

 /9. Shell somewhat depressed (surboissde). 



4th Group. Imperforatce, Fdr. 



1. Mouth rounded ; peristome open. (Helix gattata, Ac.) 

 Mouth sinuous ; peristome strongly reflected. (Helix, squa- 



mota, Ac.) 



3. Mouth turning over (versante) ; columellar border sinuous, 

 flattened, and subdentated. (Ildix coynala, Ac.) 



IV. Sub-genus. Helicodonta, Fdr. (Tomoyeret, Montf. ; 



Anottoma, Lain.). 



1st Group. The Grimaces, Pernmotip, Fur. (Helix dentiens, Ac.). ' 

 Aperture defended by one or more elongated and internal lauiimc. 



2nd Group. Lamellatir, Fer. 

 * Many lamina). (Helix carabinala, Ac.) 

 " A single lamina. (Ilelix labyrinthica.) 

 IVrUtome furnished with large teeth, one of which at the base of 



the columella forms a gutter. 



3rd Group. Maxillattr, Polyduntet, Montf. (Helix imperator, Ac.). 

 Mouth reversed, furnished with elevated folds, the impressions of 



which are visible outwards. 

 1th Group. Anostomes, Fdr. ; Anottoma (Helix rinyent, Ac.), 



Strep/axil, Gray. 



rior border of the aperture furnished near the peristome with 

 elevated longitudinal folds, the impressions of which are visible 

 outwards. 



5th Group. Imprettce (Ilelix cepa, Ac.). 



V. Sub-genus. Helicigona, Fer. 



Umbilicus covered. 

 1st Group. Carocolla, Montf. (Helix anyutoma, Ac.). 



Umbilicus masked or visible. 

 2nd Group. Vorticet, Ok. (Helix marginata, Ac.). 



VI. Sub-genus. Ilelicella, Fdr. 



Peristome reflected. 

 1st Group. Lomaatomes, Lomastoma, Fdr. (Ifelix caratcalcmis, Ac.). 



Peristomo simple. 



2nd Group. Aplostomes, Aploiloma, Fdi. 

 * VerticiUi. (Helix lineata, Ac.) 



Il'i'ilina. (Helix olivetorum, Ac.) 

 *** Patciatte. (Helix Candida, Ac.) 



Peristome bordered. 



a. Shell horn colour or brown, nearly unicoloured, rarely fasciated, 

 often hairy ; peristome rather spread ; epidermis caducous. 



3rd Group. Hyyromanet, F5r. (Helix cincteUa, Ac.) 

 P. Shell white or reddish, very much ornamented with bands or 

 small vivid-coloured lined ; epidermis insensible, never hairy ; 

 sometimes carinated ; peristome bordered but not spread. 

 4th Group. Jleliomana, Fir. 



* Shell somewhat depressed or globulose. (Hdix grot/ana, Ac.) 



* Shell trochoid ud a little carinated. (Ifelix pyramidata, Ac.) * 



VII. Sub-genus. Ilcliaatyla, Fdr. 



Columella straight ; peristome simple ; shell subdepressed. 



1st Group. A plostomefl, Aplottoma, FeY. (Helix mitella, Ac.). 



ji^lla twisted, truncated as it were at its base, or furnished with 

 an internal spiral ril, forming a gutter, and appearing under the 

 furrn of a tooth or callosity. 



2nd Group. Canaliculata, Fdr. (Helix delicatula, &c.). 

 Columella flattened, without either tooth or lamina, forming a sort of 

 gutter at its intersection with the penultimate whorl ; peristome 

 reflected. 



3rd Group. Maryinatte, Fdr. (Helix studeriana, &c.). 



it Evolutatce. Cochloides. 

 * Mouth generally toothless. 



Columella solid. 



a. En filet, not truncated at its base. 

 VIII. Sub-genus. Cochlostyla, For. 



Peristome reflected. 

 lt Group. Lomastomes, Fdr. (Hdix metaformu, Ac.). 



Peristome simple. 



2nd Group. Aplostomes, FeY. (Helix Dufresnii, &c.). 



(3. Columella solid, flattened, and truncated at its base. 



t Shell conic, or very ventricose ; aperture enlarged. 



IX. Sub-genus. Coclditoma,F6r. 



Shell conical ; mouth short ; anterior border advanced. 



1st Group. The Rubans, Ft5r. (Helix exarata, Ac.). 

 Shell ventricose; mouth very large; external border in a vertical 

 direction. 



2nd Group. Achatince. 

 +t Shell ovoid or turriculated ; mouth elongated and narrow. 



X. Sub-genus. Cochlicopa, F<5r. 



Shell ovoid ; mouth long ; exterior border in a vertical direction. 



1st Group. The Polyphemes, Montf. (Hdix Priamus, Ac.). 

 Shell turriculated ; mouth short ; external border a little advanced. 



2nd Group. Styloides, Fe"r. (Helix fttlminea, Ac.). 

 Shell perforated or umbilicated; umbilicus masked or uncovered; 

 peristome simple. 



a. Whorls of the spire equalised ; the last whorl shorter than the 

 others united. 



XI. Sub-genus. Cochlicetta, Fer. 



Only group, Twritce, Fdr. (Hdix conoidea, Ac.). 

 /3. Last whorl of the spire generally larger and longer than the 

 others united. 



XII. Sub-genus. Cochlogena, F(5r. 

 t Peristome simple or thickened, but with sharp edges. 



a. Shell umbilicated ; columella straight. 



1st Group. Umbilieata, F<5r. (Helix flammata, Ac.). 



0. Shell perforated ; columella twisted. 



2nd Group. Perforates, FeY. 

 * Shell oblong. (Ilelix fasciolata, Ac.) 

 '* Shell ovoid. (Helix cottulata, Ac.) 

 +t Peristome reflected or dentated. 



Mouth crescent-shaped, without either teeth or folds ; peristome 

 reflected and regular; columella twisted, perforated; last whorl of 

 the spire sometimes shorter than the others united. 

 3rd Group. Lomastomes, FeY. 

 * Last whorl of the spire larger and longer than the others united, 



shell ornamented with vivid colours. (Helix Favannii, Ac.) 

 ** Last whorl shorter and less than the others united; shell uni- 

 coloured. (Helix Beticnta, Ac.) 



Mouth short, crescent-shaped ; peristome simple or thickened and 

 regular ; columella twisted, more or less projecting and bent, or 

 furnished with a plait which turns upon it and makes it appear 

 Mibtruncated ; umbilicus masked or exactly closed ; last whorl of the 

 spire sometimes shorter thau the others united. 



4th Group. Helicteres, Fdr. (Ackatinella, Sw.). 

 * Shell coniform. (Ildix vuljrina, Ac.) 

 ** Shell turriculated. (Helix turritella, Ac.) 

 *** Shell ovoid. (Ilelix tristis, Ac.) 



Mouth angular at its extremities, or overlaid superiorly, often 

 narrowed by the sinuosities of the external border ; columella large, 

 more or less spiral, and forming a plait more or less projecting in 

 the aperture. Peristome thick and reflected ; last whorl of the spiro 

 longer and more convex than the others united. 



5th Group. Stomotoides, Fer. (Hdix Auris Lcporis, Ac.). 

 Mouth crescent-shaped, rather angular at its extremities, most fre- 

 quently furnished with short teeth at the peristome, which is bordered 

 or a little opened out or reflected ; never any lamina) ; columella 

 twisted, hollow, flattened at its base, or forming a -protuberance ; 

 generally perforated. 



6th Group. Dontostomes, Fdr. 



(*) Last whorl of the spire larger and longer than the others 

 united. (Helix A urii Borit, &c.) 



