38 THE NAUTILUS. 



uals were not numerous until the town was reached, where in some 

 places the bed of the stream was literally covered with Goniobasis. 

 A large spring at the edge of the town furnished several species. 



The Coosa river at Farmer, Shelby Co., offered no good collect- 

 ing places, but farther up the stream at Ft. William's Shoals the 

 stream was explored for considerable distance with very satisfactory 

 results. In the clear, shallow water everything was plainly visible, 

 the colors of the shells often showing with remarkable distinct- 

 ness. Shoal creek, below Farmer, contained but few individuals. 



At Wilsonville only one small shoal was searched. 



At Wetumpka there are more accessible places for collecting than 

 at any of the other Coosa river localities visited. 



The Tallapoosa river above Tallassee, is a much broken stream 

 caused by a rough rock-bed, with a considerable fall. 



The Pleuroceridse were looked for closely, and especially the Coosa 

 river forms ; but many described species and others listed from that 

 stream were not found. Some of them were undoubtedly overlooked 

 or are to be found in other situations than those explored, but I 

 think the earlier collectors in some way mixed their collections ; and 

 species are credited to the Coosa river which were not found there, 

 while some of the Coosa river forms were credited to other streams. 

 This subject is open for further investigation. 



For aid in determination of the species, thanks are due Prof. Pils- 

 bry for kindly comparing a large part of the Pleuroceridce and part 

 of the Unionidee with specimens in the Academy of Natural Sciences, 

 and for describing some new forms of Limnseidse. To Mr. Bryant 

 Walker for his excellent work with new forms of Somatogyrus, etc. 

 and identifying part of the Helicidce and Unionidee. And to Dr. 

 Sterki for identifying the Corbiculidse. 



Very little attention was given the land shells and the fresh-water 

 species which inhabit muddy situations. The Unionidce were taken 

 as they were noticed while looking for the Pleuroceridce, so that this 

 list is not as full as it might otherwise have been. 



In the genus Schitostoma or Gyrotoma, the fissure appears to be 

 the most constant character, while the striae, carinas, nodules, bands, 

 ground-color and outline, all vary more or less. 



FAMILY PLEUUOCERIDJE. 



Pleurocera annul Iferum Con. Warrior, common. 



