NERITELLA. 39 
lum, reclivata and picta are marine, and there- 
fore should not have been included; one, Jay- 
ana, is fluviatile, but belongs to the European 
group undoubtedly: and ‘one, Californica, is 
marine, and belongs to the Philippine Islands 
group of species. The remaining species I 
describe. 
1. NERITELLA SHOWALTERI, Lea. 
Plate 16, fiz. 2. 
Shell smooth, rounded, semi-transparent, 
yellowish horn-color; spire very much de- 
pressed; sutures slightly impressed; whorls 
three, ‘inflated; aperttive semirotund; inner 
lip dilated, white, thickened, without teeth 
and incurved; outer lip acute, dilated and 
thin. Operculum —? 
Diameter 5, alt. 4-5 mill. 
Coosa River, Shelby Co., Alabama. 
A very rare species, of which Dr. Lea only 
received four specimens, one of which he 
obligingly presented to the Academy of Natu- 
ral Sciences. 
