POLYGYRA. 



77 



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

 P. exoleta Binn., iii. 151. 



zaleta Binn., olim. 

 P. multilineata Say, iii, 150. 



P. divesta Gld, iii, 152. 



dejecta and adject a 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. perigrapta Pils. v. carolinensis Lea, viii, 153. 



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



sargenti J. & P, not Bid. denotata Fer. 



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. 



jinjnllfiiaita Alb. 

 P. wheatleyi Bid., iii, 151. 



P. christyi Bid, iii, 151. . 

 P. mitcbelliana 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 deflexed in front. Ajifi-lnrc 

 basal, narrow, obstructed by an oblique blade-like pnr'utnl tooth 

 parallel to the reflexed basal Up, 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 semiuis and its duct, the latter being quite short (pi. 31, fig. 

 27, P. spinosa). 



