POLYGYRA. 



77 



P. andrewsi W. G. B., iii, 150. 

 P. exoleta Binn., iii. 151. 



zaleta Binn., olim. 

 P. multilineata Say, iii, 150. 



P. divesta Old., iii, 152. 



dejecta and abjecta Gld. 

 P. wetherbyi Bid., iii, 152. 

 P. roemeri Pfr., iii, 152. 

 P. dentifera Binn., iii, 152. 



P. appressa Say, iii, 148. P. obstricta Say, iii, 148. 



linguifera Lam. helicoides Lea. 



v. peri^rapta Pils. v. carolinensis Lea, viii, 153. 



P. sargentiana J. & P., viii, 153. P. palliata Say, iii, 147. 



sargenti J. & P., not Bid. denotata Fe>. 



P. subpalliata Pils. notata Dh. 



P. elevata Say, iii, 148. 

 tennesseensis Lea. 

 knoxvilliana Fer. 



P. clarki Lea, iii, 149. 



P. pennsylvanica Green, iii, 151, 





P. thyroides Say, iii, 152. 



thyroidus Say. 



v. bucculenta Gld., iii, 153. 

 P. clausa Say, iii, 153. 



ingallsiana Shutt. 



jugallsiana Alb. 

 P. wheatleyi Bid., iii, 151. 



P. christyi Bid., iii, 151. 

 P. mitchelliana Lea, iii, 151. 

 P. downieana Bid., iii, 153. 

 P. lawi Lewis, iii, 153. 

 P. mobiliana Lea. 

 P. jejuna Say, iii, 153. 



Section Stenotrema Rafinesque. 



Shell small, compact, imperforate or umbilicate ; snbglobose, 

 globose-depressed or lens-shaped the periphery varying from rounded 

 to acutely keeled ; surface dull, smooth, generally hairy. Whorls 5- 

 6, closely revolving, the last suddenly defiexed in front. Aperture 

 basal, narrow, obstructed by an oblique blade-like parietal tooth 

 parallel to the reflexed basal lip, the latter often notched in the 

 middle. Last whorl generally having in its last fourth a short 

 transverse partition on the axis. Type P. stenotrema Fer. (see pi. 

 31, figs. 22, 23, 24, P. monodon var. alicice'). 



Animal externally as in Triodopsis. 



Genital system having the penis notably longer than the recepta- 

 culum seminis and its duct, the latter being quite short (pi. 31, fig. 

 27, P. spinosa). 



