HELIX §. 55. 291 



,j. Minor, cingulis distantibus 6 — 7 lalcriliis: diani. niaj. 1«, niin. iG, 

 ult. W mill. (Spec.) 



Ilelix midtilineata var. Chemn. 1. c. t. 71. f. 19. 20. 

 Habitat in America boreali : Illinois et Missouri. 



759. H. pennsylvanica Grecn. 



T. obtecle perforata, subglobbsa, tenuis, pellucida , luleo- 

 cornea, subtiliter oblique costulata; anfr. 5 planiusculi, ultimus 

 ad aperturam subconstriclus; apertura lunaris; perist. late re- 

 flexum, intus albo-labiatum , raargine columellari subrecto, ex- 

 panso, umbilicum obtegente. — Diam. maj. 17, min. 15, alt. 1 1 — 

 12 mill. (Coll. Nr. 463.) 



Helix pennsylvanica Green Contrib. to Maclunan Lyc. N. L p. 8. 



— — Binn. in Bost. journ. I. p. 483. t. \%. 



— — Pfr. Symb. II. p. 36. 



— — Chemn. ed. II. Ilelix N. 442. t. 73. f. 4. 5. 



— claiisa Say in Philad. journ. IL p. 154. Nec Ralin. 



— — Say Amer. Conch. t. 37. f. I. 



— — Binn. in Bost. journ. I. p. 482. t. 15. 

 Tridopsis thyroidus var. edentida Beck ind. p. 23? 



Habitat in America boreali: Pennsylvania , Ohio, lllinois. 



Obs. Differt ab H. multilineata spira elatiore et lamina umbilicum obte- 

 gente mullo minus expansa , ab H. lliyroide nmbiiico omnino clauso . apertura 

 edentula, elc. 



760. H. Mitchelliana Lea. 



T. superne obtuse conica, inferne inflata, longitudinaliter et 

 subtiliter striata, cornea, diaphana, imperforala; anfr. 5; aper- 

 lura subrotundata; labrum subreflexum; columella laevis. — 

 Diam. 0,7, long. 0,4 pofl. (Lea.) — Diam. maj. 19, alt. 12 mill. 

 (exic.) — Coll. Nr. 464? 



Helix Mitchelliana Lea obs. II. p. 87. t. 23. f. 71. 



— — ? Ciieinn. ed. U. Helix N. 332. t. 56. f. 6 — 8. 



Habitat in America boreali : Ohio. 



Obs. «Affinis clausae et jejunae Say. Slriae majores, quam harum; labrum 

 magis acutum, quam clausae». — Conf. H. Ihyroides Nr. 900. 



761. H. plicaria Lamarck. 



T. obtecte perforata, orbiculato-depressa, violacescenti-fusca, 

 basi pallidior, oblique gi^anulato-costata; anfr. ^J/;! convexi, ulti- 

 raus autice valde deflexus; apei^tura subhorizontalis, angusta, 

 subovalis, inlus alba; perisL acutum, angulatim lalissinie expan- 

 sum, inlus incrassatum, marginibus callo junctis. — Diam. maj. 

 20, min. 16, aU. 10 — 11 mill. (Coil. Nr. 465.) 

 Helix pUcaria Lam. Enc. meth. t. 462. f. 3. 



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