THE NAUTILUS. 



VOL. XXVIII. MARCH, 1915. No. 11 



ON PALTJDINA COARCTATA AND INCRASSATA LEA. 



BY BRYANT WALKER. 



The descriptions of both of these species were read by Dr. 

 Lea before the American Philosophical Society on Dec. 16, 

 1842 and were published on or before Jan. 3, 1843. Since that 

 time they have led a varied and precarious existence at the 

 hands of subsequent authors. Lea's types were, in both in- 

 stances, single, imperfect specimens received from Dr. Foreman 

 without any more precise locality than that of "Alabama." 

 Lea never figured either of his species. But this was done by 

 W. G. Binney twice, though the two figures in each case are so 

 dissimilar that it does not seem possible that they could have 

 been drawn from the same specimens, were it not so stated by 

 the author. 



Binney in his preliminary "Descriptive Catalogue of the 

 species of Amnicola, Vivipara, etc. of North America", pub- 

 lished by the Smithsonian Institution in 1862 and purporting 

 to be " proof ", not only published a figure of the type of coarc- 

 ata, but also one of "a perfect specimen " from the Lea collec- 

 tion. In this paper he recognized the species as a valid one, 

 but added to it as synonyms the exilis and lima of Anthony. 



In the same paper he also figured the incrassata and gave it 

 specific rank. 



In this final work, "Land and Freshwater Shells of North 

 America, Part III," (1865), he omitted the figures of covrrtata 



