Notice of Land and Freshwater Shells. 



Helix polyg^yrella, nov. sp. 



T. late umbilicata, discoidea, planulata, Tiitida, translucida, luteo-corneS., 

 superne costulata, costis ad aperturam obsoletis, basi lavinscula, spira 

 vix elevata ; anfr. 7-8 convexiusculis, lente accrescentibus, ultimo antice 

 breviter deflexo, intus seriebns dnobns remotis trium dentium munito ; 

 umbilico ad apicem pervio; apeitnra subverticali, obliqiia, Imiato-ovali ; 

 perist. superne depresso, albo, simplici, valde incrassato, inarginibus dente 

 pliciformi, elevato, albo, triangular! junctis. 



Shell widely nmbilicate, discoidal, flat, shining, translucent, 

 yellowish horn colored, ribbed above, the ribs obsolete near the 

 aperture, base rather smooth; spire scarcely elevated; whorls 

 7-8, somewhat convex, gradually increasing, the last slightly 

 deflexed above, armed within with two rows of three teeth, 

 seen through the outer wall; umbilicus pervious, of equal size 

 to the apex; aperture subvertical, oblique, lunate-oval; peri- 

 stome depressed above, white, simple, much thickened within, 

 the margins joined by a white plicifonn elevated triangular 

 tooth. ^ 



Diam. maj. 11^, min. IO5, Alt. 5 mill. 



Station. — Inhabits moss and decaying wood in the dampest 

 parts of the spruce forests. 



Habitat. — Common on the Coeur d'Alene Mountains, espe- 

 cially on their eastern slope. J. G. Cooper! 



lit^tnarJcs. — This very interesting species is unlike any shell, 

 with which we are acquainted, hitherto found on the North 

 Aniericari Continent. Although entirely distinct from the 

 Brazilian II. polygyrata Born it has some affinity with it, espe- 

 cially as regards the form generally, and the ])resence of the 

 internal teeth. II. polygyrata has live teeth within the last whorl, 

 three on the under surface of the outer wall, and tw^o opj^osite to 

 the others on the exterior of the penultimate whoi'l. Our species 

 has two distinct rows of three teeth, all the teeth being on the 



