122 HELIX. 



entering, more or less dilated, peristome slightly expanded, extremi- 

 ties converging; dark brown, unicolored, or obscurely banded, Azores, 

 Madeira Is. etc. Type, H. undata, Lowe. 



Section VIII, IBERUS, Montfort, 1810. 



Narrowly umbilicate or imperforate, globose, or depressed, periph- 

 ery sometimes sharply keeled, whitish, obsoletely fasciate, more or 

 less rugose, whorls 4-5, the last anteriorly descending ; aperture very 

 oblique, peristome expanded, labiate, reflexed at columellar margin. 

 Type, H. muralis, Mull. Characteristic of middle and southern 

 Italy and Sicily, but found throughout southern Europe. 



Section IX, POMATIA Beck, 1837. 



Large, globose, striate, rather thin, imperforate or narrowly per- 

 forate, unicolored or five banded, whorls convex, rapidly increasing, 

 last large, ventricose, descending anteriorly; aperture lunate-orbicu- 

 lar, peristome expanded or sharp, callous within, columellar margin 

 reflected. Type JT. pomatia L. Distribution, Europe, Western 

 Asia and Northern Africa. Introduced by commerce into America 

 etc. 



Section I, TACHEA Leach, 1820. 



This group comprises the most abundant and conspicuous European 

 snails. Several species have been introduced by commerce into 

 distant countries. 



The shells are bright colored and banded, the color pattern very 

 variable. 



Cepaea Held, 1837, and Archelix Albers 1850 are synonyms. 

 ^ The jaw in Tachea (PI. 35, fig. 15,) is stout, arched, with strong 

 ribs, few in number, denticulating either margin. The dentition is 

 characterized by the obsolecence of side cusps to the central and 

 adjacent lateral teeth ; marginal teeth with several cusps. 



H. NEMORALIS, Linn. PI. 34, figs. 94-96, PI. 35, fig. 97. 



Imperforate, subglobose conic, irregularly striate, yellow, with five 

 sharply defined deep brown bands, sometimes coalescent, or unicolored 

 white, pink, yellow or bright corneous; whorls 5, the last slightly 

 descending in front; aperture rotund-lunar, peristome expanded, 



