1896.] NATURAL SCIENCES OF PHILADELPHIA, 505 



151. Unio texasensis Lea. 



Reelfoot Lake, Samburg (69215). 



INIuch larger than the typical form from central Texas, length 

 56, breadth, 30 mm. 



152. Unio trapezoides Lea. 



Reelfoot Lake, Samburg (69216). 



Two young specimens. The species has not before been reported 

 from so far north, east of the Mississippi, so far as I know. 



153. TJnio triangularis Barnes. 



Tennessee River, above Knoxville (68378). 



154. Unio tuberculatus Barnes. 



Big Harpeth River, near Belle vue, Davidson Co. (68345) ; Wolf 

 River, below Raleigh, Shelby Co. (68703). 



The specimens from the Big Harpeth belong to the large, densely 

 pustulose, white nacred, northern race. 



155. Unio tumescens Lea. 



Tennessee River, near Knoxville (69374) ; Emory River, Harri- 

 man (69375) ; Clinch River, above Patton's Ferry (69376). 

 Described by Lea from Alexandria, La, 



156. Unio turgidus Lea. 



Wolf River, near Raleigh (68384). 

 Described from New Orleans. 



157. Unio undulatus Barnes. 



Clinch River, above Patton's Ferry (69209) ; Big Harpeth River, 

 near Bellevue (68344). 



On account of the prior Unio undulatus Say (now Alasmodonta 

 undulata), the name of this well-known species must be changed, 



158. Unio ventricosus Barnes. 



Big Harpeth River, near Bellevue, Davidson Co. (68328). 



159. Unio verrucosus Barnes. 



Big Harpeth River, near Bellevue, (68343) ; Tennessee River, 

 above Knoxville (68349) ; Holston River, 1 mile above junction 

 with Tennessee River (68350), 



160. Alasmodonta complanata Barnes. 5 



^The diverse origin of various elements of the so called genus Margaritana 

 has been demonstrated by Mr. C. T. Sinapson. It is practically certain that 

 the group of M. complanata, rugosa, etc., arose from a different stock of Unio 



