326 NATURAL HISTORY BULLETIN. 



Discussing chiefly the loess of the lower Mississippi Dana 

 also says:* "The loess of the Mississippi contains numerous 

 fresh-water shells, among them Paludina pondcrosa Say, Me- 

 lanin canaliculate* Say, Cyclas rivularis Say, Cyclostoma lapi- 

 daria Say, PJiysa hcterostropha Say, Linuuva clongata Say, 

 Planorbis bicarinatus Say, Valvata tricarinata Say, Unios, etc." 



The first three species of this list, and the Unios, are fluv- 

 iatile, Cyclostoma (= Pomatiopsis) lapidaria is terrestrial, and 

 the remaining species are chiefly pond snails. Evidently 

 these shells came from the deposit below loess, noted on p. 304 

 and referred by Wailesf to Lake Marl, which he properly rec- 

 ognized as distinct from the loess. 



These additional citations add nothing to the weight of the 

 testimony concerning the occurrence of fluviatile shells in the 

 loess. They only show additional sources of the errors which 

 have been thus transmitted to those who have not investigated 

 the details of the case for themselves in the field. 



*P. 548, 1. c. 



tPp. 231 and 283, 1. c. 



