31 



not parallel ; next is a large tooth, wliicli terminates at the outer mai*- 

 gin of the lip, and next a fourth on the collumella, which enters a 

 large deep indentation in the central region of the shell ; lip broadly 

 reflected, but rather sharp, columellar part very Avide and concavely 

 flattened ; umbilicus wanting. 



Greatest breadth .95 inch ; least breadth .8 inch ; height .58 inch. 

 Helix torrefacta. Shell conoid, with a very thin transparent 

 epidermis, on the upper whorls, which is a little thicker and straw- 

 colored on the lower whorls ; smooth or with almost imperceptible 

 striae of growth ; spire like that of H. CooMana, Fer., but a little 

 more elevated ; whorls eight, short, moderately convex, with a well 

 impressed suture ; last whorl with the base, (intermediate between 

 that of H. Cookiana and H. epistylium, Miill.) having its central re- 

 gion rather deeply but not very widely indented ; aperture lunate ; 

 labrum sharp ; columella somewhat twisted and produced rather ob- 

 liquely ; around the base of the last whorl within is a lamella, which 

 slopes inwardly as it rises. 



Dimensions of two varieties : No. 1 : greatest breadth .7 inch ; 

 least breadth .63 inch; height .7 inch. No. 2 : greatest breadth .6 

 inch ; least breadth .55 inch ; height .7 inch. 



Helix epistyliulu.'m. Shell conoid ; white ; with microscopic 

 striae of growth ; spire with very convex outlines ; apex very obtuse ; 

 whorls six and one-half, a little convex, Avith a well impressed suture ; 

 last whorl with a subangular periphery ; aperture lunate, without 

 any internal lamella ; lip sharp ; umbilicus very narrow, rather deep. 

 Greatest breadth .175 inch ; least breadth .16 inch ; height .17 

 inch. 



Except in its minute size this species much resembles H. epistyli- 

 um, and still more closely H. Cookiana. 



Helix pila. Shell very globular ; white, translucent ; w-ith ex- 

 cessively fine striae of growth and microscopic spiral lines ; spire with 

 very convex outlines ; apex very obtuse ; Avhorls more than six, quite 

 convex, with a well impressed suture ; aperture lunate, except as 

 interrupted by the intrusion obliquely of a large uneven abruptly ter- 

 minating columella ; lip very thin and sharp ; within, nearly half 

 way up the outer side, is a high lamella, which after entering half 

 the length of the last whorl suddenly diminishes to a line ; umbilicus 

 wanting. 



Greatest breadth .G inch ; height .50 inch. 



Helix lamellifera. Shell hemispherical ; brownish horn color; 



