DESCRIPTION. 171 



Fig. 4. H. Colum?ia, 



Shell tapering ; whorls contrary ; aperture ob- 

 long. 



Lister Conch, tab. 38. fig. 37. 



Specimen white, pellucid, with purplish longi- 

 tudinal rays; longitudinally and transversely striate. 



Inhabits .... 



Fig. 5. H. stagnalis. 



Shell imperforate, ovate, subulate ; aperture 

 ovate. 



Lister Conch, tab, 123. fig. 21. 



Specimen pale yellowish brown, darker towards 

 the apex ; very finely striate longitudinally, very 

 thin and brittle ; body turgid ; spire small ; aper- 

 ture wide ; outer lip not margined. 



Inhabits the stagnant waters of Europe. 



Fig. 6. Nerita glaucina. 



Shell smooth ; spire rather obtuse ; umbilicus 

 half-closed; columellar lip gibbous, of two colours. 



Lister Conch, tab. 568. fig. 19. 



Specimen yellowish brown, with cinereous clouds; 

 upper part of the whorls marked with short ob- 



