foe, Ne@rrus: 
VoL. x. JUNE, 1896. No. 2 
NOTE ON NERITINA SHOWALTERI LEA. 
BY WM. H. DALL. 
In February, 1861, Dr. E. R. Showalter of Alabama sent four 
small shells without opercula or soft parts to Dr. Isaac Lea. They 
were obtained ten miles above Fort William, Shelby Co., Alabama, 
from the Coosa River. Three of these specimens are now in the 
National Museum, with the original labels of Showalter and Lea. 
The species was described under the name of Neritina Showalteri by 
Dr. Lea, who observed that it was the first instance of the discovery 
of true freshwater Neritina, like those of Europe, in our southern 
waters. The note in which the description is embodied was read 
Feb. 12, 1861 and published in the Proceedings of the Academy of 
Natural Sciences, vol. xiii, p. 56, March 19, 1861, and also separ- 
ately. 
Since that time for many years no notice of the species as collected 
has come to my knowledge and I began to suspect that Dr. Showalter 
had been imposed upon by some one who had given him, as obtained 
from the Coosa River, some specimens of Neritina fluviatilis of Eur- 
ope, to which these shells bear a marked resemblance, except that 
they are smaller and without any dark markings upon the olivaceous 
surface. It seemed very curious that a species of the section Theo- 
doxus, to which Neritina fluviatilis is now referred, and which is not- 
ably profuse in individuals when occurring at all, in Europe, should 
be found only in one small stream in our Southern States and very 
sparsely there. Of numerous collectors on the Coosa River since 
