1896.] NATURAL SCIENCES OF PHILADELPHIA. 497 



ivata " Lea," filum Lea, spinaUs Lea and torta Lea belong to the 

 the prior genus Pleurocera Rat"., and, therefore, are to be eliminated 

 from Elimia. Holstonia Lea belongs to the prior genus Lithasia 

 Hald. Apis Lea is a Pachychilus. The other species are true Go7i- 

 io bases. 



Gyrotoma Shuttlew., 1845, ♦ 



Synonyms Schizostoma and Schizocheilus Lea (preoc). Apella 

 Mighels, MS., 1860. 



Anculosa Say. 



73. lo spinosa Lea. 



Holston River, 3 miles from Knoxville (69258) ; Tennessee 

 River, near Knoxville (69252) ; Nolaehucky River., 5 miles south 

 of Greeneville (69251) ; in the Indian shell heaps, Williams 

 Island, Tennessee River (69255) ; Indian mound, junction Holston 

 and French Broad (69254) ; Indian mound, Patton's Ferry, Nola- 

 chucky River (69265). 



74. Lithasia geniculata Hald. 



Indian shell heaps, Williams Island, Tennessee River (69240) ; 

 Emory River, near Harriman (69242) ; Tennessee River, near 

 Knoxville (69241) ; Clinch River, below Patton's Ferry (69239). 



75. Lithasia verrucosa (Raf.). 



Tennessee River, near Chattanooga (69332) ; Tennessee River, 

 near Knoxville (69247) ; Aboriginal shell heaps, Williams Island 

 (69248) ; shell heap, junction Holston and French Broad Rivers 

 (69264). 



76. Lithasia venusta Lea. 



Big Harpeth River, near Bellevue (69293, 69294). 



77. Lithasia stygia (Say). 



Big Harpeth River, near Bellevue (69333). 



These shells, while worthy of the Styx when unwashed and black 

 with iron deposit, are of a beautiful green with darker bands when 

 this incrustation is removed. 



78. Pleurocera undulatum (Say). 



Clinch River, above Patton's Ferry (69313) ; Holston River, 1 

 mile above French Broad (69312, 69314). 



Pleurocera undulatum is here understood to cover the following 

 nominal species, all of which seem to be connected by inappreciable 

 degrees when a large series is examined : Melania excurata Con., 



