8 THE NAUTILUS. 



draining and filling of swamps and marshes, the construction of 

 dams, etc., all tend toward lessening the fauna and flora of a 

 given area. 



NEW LAND SHELLS FEOM ALABAMA AND TENNESSEE. 



BY GEO. H. CLAPP. 



POLITA CUMBERLANDIANA, n. Sp. 



Shell widely umbilicated, flattened, very slightly convex 

 above and below, glossy, thin and translucent, light horn color, 

 regularly but lightly sculptured across the whorls by curved, 

 closely set radiating impressed lines parallel with the lines of 

 growth which are very faint; spire flattened; stature shallow; 

 whorls about 4, rapidly increasing, the last decending at the 

 aperture which is elongate-oval flattened above, lip very slight- 

 ly reflected at the columellar insertion; umbilicus wide, display- 

 ing all the whorls and contained about 4 times in the diameter 

 of the shell. 



Greater diameter 3, lesser 2.5, altitude 1.25 mm. 



Collected by Herbert H. Smith on the Cumberland Plateau 

 near Stevenson, Jackson Co., Alabama, also near Anderson, 

 and near Sherwood, Franklin Co., Tennessee. 



Types No. 9157 of my collection. Paratypes in the collec- 

 tions of the Academy of Nat. Sci., Philadelphia and Bryant 

 Walker, Detroit, Mich. 



At first glance this species may be taken for immature V. 

 radiatula as the general shape and the sculpture of impressed 

 radiating lines are the same, but it is uniformly small with the 

 same number of whorls, the sculpture is weaker and the shell 

 more flattened. Under high magnification there is merely the 

 faintest trace of impressed spiral sculpture. It is much smaller 

 than Polita rhoadsi. 



