SUCCINEA. 39 



SYNONYMS AND KEFERENCES. 



Succinea lineata W. G. Binney, Proc. Acad. N. S. of Phila. vol. ix. p. 19 ; 

 Notes, p. 1, (February 1857). Proc. Boston Soc. N. H. vol. 

 vi. p. 155, (April, 1857). 



DESCRIPTION. 



Animal not observed. 



Shell oblong-ovate, with three very convex whorls ; 

 spire elevated, acute ; surface marked with irregular wrin- 

 kles of growth, between which are coarse parallel revolv- 

 ing lines, somewhat removed from each other. Aperture 

 large, about as long as one half of the whole length of the 

 shell, oval ; columella folded ; a deposition of callus on 

 the parietal wall of the aperture. 



Greatest diameter, 6 ; alt. 12 millimetres. 



Geographical Distribution. Collected in considerable 

 quantity by Dr. F. V. Hay den, (Yellowstone, Expl. Ex.) 

 on high hills near Fort Union, Nebraska Territory. 



Remarks. The specimens collected being dead and 

 eroded, it is impossible to say what is the color of the 

 shell when fresh. It is probably ashy white, resembling 

 the true S. campestris of the Southern States. The re- 

 volving lines which distinguish it are most apparent on 

 the middle of the body whorl. These are quite coarse, and 

 placed at irregular intervals ; — on some specimens scarcely 

 discernible. The aperture is unlike that of any other of 

 our species ; being correctly egg-shaped, — it is nearest in 

 form to that of S. campestris, but is less expanded. The 

 parietal wall of the aperture is unusually horizontal. 



In general aspect it resembles somewhat S. vermeta, 

 but is distinguished from that shell by its more oval shape, 

 and the greater convexity of the whorls. It is the heaviest 

 American species. 



This species must not be confounded with S. lineata 

 DeKay. 



