PALUDINA INTEGRA. 11 



"Inhabits the waters of the Missouri. 



"Length 1-4 of an inch. [1.4 in.? or li in.?] 



"Very much resembles P. decisa; the spire, 

 however, is more elongated, and never trun- 

 cated at the apex, but always acute." — Say. 



Geographical Distribution. Inhabits the 

 Santee canal, South Carolina, (fig. 3,) T. A. 

 Conrad: Ohio, (figs. 1, 2,) J. G. Anthony: the 

 Mississippi, in Iowa Territory, (fig. 4,) Dr. W. 

 Blanding. 



OBSERVATIONS. 



I have made use of Say's description and 

 remarks, as this is a species ? about which there 

 is some uncertainty. The shells here figured 

 are generally received as P. integra, although 

 every one must have remarked the discrepancy 

 between their size and that given above. Mr. 

 Say's time, however, was too valuable to be 

 spent in searching for large specimens; we 

 accordingly find that he described his Paludina 

 subcarinata from a specimen having three 

 whirls; and figured Melania virginica from one 

 with but five; whilst good specimens of both 

 shells have just twice the number of whirls 

 given. It is possible that the size, as given in 



