238 HELicrD^. 



abundantly under fragments of wood, in damp places 

 near the water's edge, in company witli Helix chersina 

 and Pupa modesta." 



On its upper surface, it appears to be identical with 

 Helix indentata ; while on the base, its resemblance to 

 Helix arhorea is striking. It appears to be a widely 

 diffused, and very common species. It is often found in 

 company with H. arborea. 



67. HELIX OTTONIS, PfeIFFER. 

 Plate XXIX. a, Figuee 3. 



H. testa depressa, pallide cornea, pellucida, umbilicata, 

 basi sub-plana ; anfractibus quatuor convexiusculis, striatis ; 

 labro tenui, acute; apertura sublunari. 



SYHONYMS AND KEFEKENCES. 



Sdix Ottonu, Pfeiffek, Wiegmann's Archiv. 1840, I. 251. 

 Helix arborea, (variety) Pfeiffee, Monog. Helic. Viv. II. 95. 



DESCRIPTION. 



Shell small, depressed, orbicular, but not remarkably 

 transparent, of a watery horn-color, becoming opaque 

 when dead, very faintly marked by the Unes of growth. 

 Spire of about four shghtly convex whorls, the outer one 

 obscurely angular at periphery ; sutiu-e very delicate ; 

 beneath convex, with a small, well defined umbilicus. 

 Aperture crescentic, hp simple. 



Diameter one-fifth of an inch; axis one-tenth of an 

 inch. 



