UPPER TENNESSEE DRAINAGE. 525 
exchanges of rare forms. As has been mentioned above, also Walk- 
er’s collection has been examined, and incidentally some of the ma- 
terial of the U. S. National Museum, in Washington, chiefly some 
of Lea’s types, has been studied. 
It is believed that the Carnegie Museum possesses now the best 
collection representing the Upper Tennessee fauna, and with regard 
to the illustration of the distribution of the various forms, it has no 
equal, not to speak of the fine collection of soft parts. In view of 
the gradual, slow but steady, deterioration of the fauna in conse- 
quence of stream-pollution, there is great danger that the fauna will 
largely become destroyed, and that it will be impossible, in the future, 
to duplicate this collection. At the present time, conditions are fair, 
in some parts splendid; but there are already polluted streams, in 
which the fauna is gone. Such are: the Powell River, for a certain 
distance below Big Stone Gap, Va. (wood extracting plant); the 
North Fork Holston for a distance below Saltville, Va. (salt and 
plaster of Paris industries) ; French Broad River at Asheville, N. 
Car. (pollution comes—as I have been informed—from Davidson 
River, farther up) ; Big Pigeon River, from Canton, N. Car., all the 
way down (woodpulp and paper mill) ; Tellico River below Tellico 
Plains, Tenn. (old wood pulp and extracting mill). The building 
of dams (for water power, etc., for instance in Nolichucky River 
near Greenville, Tenn.) also has a deteriorating effect upon mussel 
life, and all this surely will increase in the future. 
BIBLIOGRAPHY. 
Aside from the well-known older papers of Lamarck, Say, Rafinesque, 
Conrad, Call, and others, the following have been principally used in the 
preparation of this paper. 
Frierson, L. S. 
1911. Remarks on Unto varicosus, cicatricosus and Unio compertus new 
species. Nautilus, 25, 1911, pp. 51-54. 
1914a. Remarks on Classification of the Unionide. Nautilus, 28, 1914, 
pp. 6-8. 
1914b. Observations on the Genus Symphynota. Nautilus, 28, 1914, p. 40. 
Goodrich, C. 
1913. Spring Collecting in Northwestern Virginia. Nautilus, 27, 1913, 
pp. 81, 82; 91-05. 
Hinkley, A. A. 
1906. Some Shells of Mississippi and Alabama. Unionide. Nautilus, 
20, 1906, pp. 52-55. 
