HELIX. 105 



beneath the tufts of dead grass." The numbers col- 

 lected m these retreats are sometimes "agglutmated 

 into one mass." This habit of attaching themselves to 

 each other in numbers, during their hybernation, I have 

 not witnessed in any other of our species, but I beUeve 

 it is common in some Europelm species. 



4. HELIX PENNSYLVANICA, Green. 



» 



Plate VII. 



H. testa elevato-convexa, imperforata, corneo-rufes- 

 cente ; anfraclibus tenuiter strialis, slriis obliquis, confertis ; 

 spira elevata, apice obtuso ; apertura sub-lriangulari ; labro 

 albo, margine reflexo ; regions umbillcali depressa. 



SYNONYMS AND KEFEKENCES. 



Hslix Penneylvanica, Gkeen, Conti-ibiiiions. No. 1, p. S. 

 KiBTLAND, Oliio Report, 173. 

 BiMijEY, Boston Jour. Nat. Hist. I. 483, pi. 16. 

 Pfeiffek, Symbols, II. 36. 



Monog. Helic. Viv. I. 291. 



DESCRIPTION. 



Animal. Upper surface of a dull, uniform lead-color, 

 lower surface of the foot hghter ; about twice as long as 

 the transverse diameter of the shell. 



Shell. Convex, elevated ; epidermis yellowish horn 

 color, or russet ; whorls six, convex, with crowded, ele- 

 vated, oblique striae ; suture distinctly marked ; aperture 

 sub-triangular, contracted by the lip ; lip white, narrow, 

 VOL. II. 27 



