13 



PALUDINA PONDEROSA, Say, 



Plate 4. 



P. testa ponderosa, subconica, laevigata; striis transversis 

 minutissime corrugatis: apice obtusa: anfractibus convexis: 

 sutura valde impressa: lineis longitudinalibus recurvatis: 

 apertura ovato-oblonga. 



SYNONYMS AND REFERENCES. 



P. PONDEROSA, Say. Jour. Acad. Nat. Sc, vol. ii. p. 173. 



5> „ Amer. Conchology, pi. 30, fig. 1. 



Sowerby's Genera of Shells, fig. 2. 

 Deshayes' Lamarck, vol. viii. p. 516. 



DESCRIPTION. 



Shell ponderous, subconic, and polished, 

 having from six to seven complete whirls: spire 

 lengthened: suture deeply impressed, and ca- 

 naliculate: aperture oblong ovate, narrowed 

 and rounded posteriorly: labium thickened, and 

 conspicuous: lines of growth undeviating until 

 near their anterior extremity, where they are 

 recurvent; labrum much advanced at this part: 

 surface with very fine transverse w^avy striae, 



