HELIX. 255 



The synonyms are H. terrestris Forsk., neritoides Chema., naticoi- 

 des Drap., karalitana Prunn (teste Villa). 



A common species, easily recognized by its bubble-like form and 

 large aperture; the epiphragm is calcareous, white, very convex, 

 as if inflated from within (as, indeed, it is), and situated at the edge 

 of the aperture; the animal is deep black in color, the central region 

 of the foot below lighter. 



H. TRISTIS Pfeiffer, 1845. PL 68, fig. 13,14. 



Imperforate, globose-conic, thin and light, olivaceous yellow, five- 

 fasciate with dark chestnut, densely obliquely striate and finely 

 decussated by spiral impressed lines, especially above ; spire short, 

 conoid, apex rather large and very obtuse; sutures well impressed; 

 whorls 4, slightly convex, the first rather large, the last large, inflated, 

 indented at the axis, a little deflected anteriorly; aperture oval- 

 lunate; peristome simple, very slightly thickened, outer, basal and 

 columellar margins regularly arcuate, the latter narrowly reflexed 

 and adnate over the umbilical perforation. 



Diam. 20, alt.' 18-22 mill. 



Corsica . 



H. ceratina Shutt. is synonymous. 



Connects H. aperta with the typical group of Pomatia. 



H. A<}<;KUIVAGA Mabille, (Guide Nat 1880, No. 3.) Unfigured. 



Corsica. 



The description of this species, said to be intermediate between 

 aperta and aspersa, is not accessible to me. 



*** 



The following species are unknown to me; and are probably, for 

 for the greater part, spurious. The manner of species-splitting 

 indulged in by the "nouvelle ecole" conchologists is shown in the 

 following remarks of M. Bourguignat, prefatory to his Description 

 <lc (juefques especes italo-pomatiennes de la serie des H. ligata et 

 lucorum, in Miscellanees Italo malacologiques. He says: "Jeconnais 

 1 U2 csprces d'Helix du groupe des Pomatia. Sur les 162 especes, j'en 

 possede 151. Onze seulement manquent a ma collection." etc., etc. 

 And then follows a classification of the group into "deux grandee 

 wfions and nineteen series of species. Compare Kobelt, Cat. eur. 

 Binnenconch., who admits but thirty-three species! 



The following names are from "Miscellanees Italo-malacologiques," 

 .}. R. Bourguignat, 1883. 



