the spire. They become proportionally more elongated 

 as they advance in age, and the form, therefore, of the 

 adult, is so different from that of the young or half grown, 

 that in these states it may, very readily, he mistaken for 

 a widely distinct species. 



The colour of the shell is variable. In som.e it is pale 

 horn, more tinged with dull yellowish, than with green ; 

 in others are traces of obsolete purplish bands, and in ma- 

 ny specimens the whole shell is reddish-purple, more or 

 less obscure in different individuals. 



In the autumn it is frequently found between the 

 valves of dead Unios, in which it enters perhaps to 

 hybernate. The species is certainly allied to the vivipara.^ 

 but it cannot well be mistaken for it, as it is much less di- 

 lated, the volutions less convex ; the penultimate volution 

 is much longer in proportion to the length of the body 

 whorl, and the umbilicus is obsolete. 



REFERENCE TO THE PLATE. 



Figure 2nd is that of the adult. 

 PLATE XXX. 



PALUDINA INTERTEXTA. 



SPECIFIC CHARACTER. 



Shell with numerous, minute, transverse, epidermal 

 lines. 



