UPPER TENNESSEE, DRAINAGE. 533 
with var. analoga). In the same collection are typical cor also from 
Poplar Creek, Roane Co., a rather small stream, where we should 
expect the headwaters-form. (It happens, sometimes, that a small 
tributary of a large river has, at or near its mouth, the large-river 
form.) Lewis reports this form from the Tennessee below 
Knoxville. 
Type locality: Elk River, Ala. (and Flint River, Ala.) (topotypes 
examined, loaned by Frierson). 
Note: Conrad’s Flint River is not the one in Madison Co., but the 
one in Morgan Co., Ala. 
8. FUSCONAIA COR ANALOGA nov. var. 
Unio edgarianus Reeve, Conch. Icon. 16. Unio. 1864, pl. 15, f. 65.— 
Fusconaia appressa or edgariana Goodrich, ’13, p. 93. 
This flat form of cor (or edgarianus) has never been separated 
from the swollen typical form, probably because there never was any 
doubt about its affinity, on account of the peculiar color character 
of the shell. However, it differs from typical cor as strongly as does 
F..cuneolus from F. cuneolus appressa, and thus deserves a varietal 
name. The shell figured by Reeve as U. edgarianus surely is this, 
since the compressed shape is mentioned. Specimens with the diam- 
eter less than 50 per cent. of the length fall under this variety. 
This is the form of the headwaters and small streams. It is in 
tue Powell and-socs up to Wee Cor, Vai. isan the Clinch irom 
Needhams Ford, Union Co., Tenn. (Walker coll.) up to Cleveland, 
Russell Co., Va., and becomes quite abundant in the Virginian part . 
of this river. In addition, it is in the North Fork Holston from 
Hawkins Co., Tenn., up to Holston, Washington Co., Va. 
It has never been found in any other part of the Holston drain- 
age, or any other river or creek in East Tennessee, and its ‘restric- 
tion to North Fork Holston, Clinch, and Powell, and its continuation 
downward, as typical cor, in the Tennessee proper alone, is quite 
remarkable. 
Type locality: Clinch River, Speers Ferry, Scott Co., Va. (types 
in Carn. Mus. Cat. no. 61.6326). 
Note: The group of F. cor is also represented in the Tennessee 
