HELIX. 1Q5 



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

 lected in these retreats are sometimes " agglutinated 

 into one mass." This habit of attaching themselves to 

 each other in numbers, during their hibernation, I have 

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

 it is common in some European species. 



4. HELIX PENNSYLVANIA, GREEN. 

 PLATE VII. 



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

 cente ; anfractibus tenuiter striatis, striis obliquis, confertis ; 

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

 albo, margine reflexo ; regione umbilical! depressa. 



SYNONYMS AND REFERENCES. 



Helix Pennsylvanica, GREEN, Contributions. No. 1, p. 8. 

 KIRTLAND, Ohio Report, 173. 

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

 PFEIFFER, Symbols, II. 36. 



Monog. Helic. Viv. I. 291. 



DESCRIPTION. 



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

 lower surface of the foot lighter ; 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. 14 



