UNIO 601 
Type locality, Stones River, Tennessee. Also Roanoke 
River and Southwestern Virginia. 
Unio stonensis Lea, Pr. Am. Phil. Soc., I, 1840, p. 286; Tr. Am. 
Phileooc., ViILLG 1841, p:.195, pl.<viil, fig..5 Obs., ITI,. 1842, 
p. 33, pl. vu, fig. 5.—CueEnu, Lil. Conch., 1858, pl. xxix, 
figs. 7, 7a, 76.—Sowersy, Conch. Icon., XVII, 1868, pl. 
LXXXVI, fig. 462.—SIMPSON, Syn., 1900, p. 705. 
Margaron (Unio) stonensis LeA, Syn., 1852, p. 27; 1870, p. 43. 
The type was received by Dr. Lea from Mr. Edgar, and is 
said to have come from Stones River, ‘'ennessee. Another shell 
in his collection agreeing with this was donated by Dr. Sho- 
walter and is said to have come from Yellow Sulphur Springs, 
Montgomery County, Virginia, Roanoke River. Other shells 
are in the Lea collection from Dr. Showalter, labeled Unio 
racensis, said to come from the Roanoke River, in Washington 
County, Virginia, which are very close to, if not identical with 
stonensis. Washington County is in the southwestern part of 
the state and all the streams in it flow into the Tennessee River. 
Lastly I have seen other specimens in the collection of T. H. 
Aldrich, said to come from the Roanoke River, Virginia, which 
agree in most characters with the shell said to be from Stones 
River, Tennessee. Some of the Virginia shells are a little 
darker colored and are somewhat more rhomboid than the 
type; part of them have white nacre and there are others with 
various shades to deep purple. It seems almost improbable 
that the species should be found in the Tennessee and Roanoke 
systems, though it is no more remarkable than the similar dis- 
tribution of Lampsilis constricta. 1 am at a loss to know 
where to place this shell. Lea believed it to be near to Unio 
gibbesus and the tvpe would seem to indicate such a relation. 
Some of the Virginia material seems to show decided relations 
to Unio complanatus. 
Unio Luripus (Lea). 
Shell irregularly elliptical or subrhomboid, compressed or 
subcompressed, rather solid, inequilateral; beaks apparently 
but little elevated, their sculpture not observed ; posterior ridge 
