30 BOOK OF SPECIES. 



P. UMBiLiCATA. Minute_, cylindrical^ obtuse, 

 s\ib-pellucid ; aperture with one tooth ; lip with 

 a white reflected margin ; umbilicus open. B. 

 T. 78. 



P. MUSCORUM. Principally diff'ers from the 

 last by its tooth not adjoining the margin, but 

 being placed further in the interior of the shell ; 

 it also has a prominent white rib at the back of 

 the outer lip. B. T. 79. 



P. FRAGiLis. Turreted, pellucid, with the 

 whorls reversed, and the aperture toothless ; yel- 

 lowish brown. 1. B. T. 70. 



P. PYGMEA. Minute, fulvous horn -colour, 

 cylindraceous, obtuse ; whorls five ; aperture four- 

 toothed; peristome reflected; umbilicus very open. 

 T. 83. B. 



P. VERTIGO. Minute, reversed, horn-coloured ; 

 five whorls ; aperture with six plaits ; peristome 

 sub-reflected, sinuated; umbilicus nearly closed. 

 B. T. 86. 



P. ANTVERTiGO. Oval, vcutricosc ; aperture 

 with eight unequal teeth, three of which are su- 

 perior, and between the lips of the peristome; 

 deep chestnut, and margin of aperture whitish ; 

 minute. B. T. 85. 



P. GooDALLi. Oblong or conical, cylindri- 

 cal, brown horn-colour, semi-transparent, quite 

 smooth and glossy, except close to the sutures; 



