5380 ORTMANN—NAYADES OF 
state line, in Virginia, it is exclusively present, going up to Big Stone 
Gap, entering even a small tributary (Cane Creek, Lee Co., Va.). 
In the Holston, this form is not so well developed, and not so 
abundant, but is present nevertheless, and also has the same relation 
to lesueuriana, first being associated with it, but then being exclusively 
present. The latter is the casein North Fork Holston, in Washing- 
ton Co., Va. In South Fork Holston, it goes up to Bluff City, Sulli- 
van Co., Tenn., but accompanied by lesweuriana; but it enters here 
Wautauga River, where it is found alone. In the Holston proper, in 
a downstream direction, it is quite rare, but it has been found as far 
down as Grainger Co., so that in this region (as is the case in lower 
Clinch) occasionally all three forms of the species may be obtained 
together. 
Type locality: Powell River, Va. (topotypes examined). 
Note: The color of the soft parts and eggs in the pilaris group 
varies greatly. The soft parts may be of the orange type, and the 
eggs (and placentz) may be red: this is chiefly the case in Powell 
and upper Clinch rivers. Elsewhere, in Holston, French Broad, and 
Tennessee, pale soft parts, with whitish eggs prevail. 
5. FUSCONAIA CUNEOLUS (Lea), 1840. 
Unio cuneolus Lea, ’40.—Unio cuneatus Reeve, Conch. Icon. 16. 
Unio, ’64, pl. 16, f. 73.—Umnio cuneolus Lewis, ’71—Unio cune- 
olus Pilsbry & Rhoads, ’96.—Pleurobema cuneolus Simpson, ’14, 
P. 743. 
This is not a Pleurobema, but a Fusconaia, taking the place of the 
group of F. flava (Raf.) (= rubiginosa Lea) in the upper Tennessee 
region. It is a very good species. 
The original and typical cuneolus represents a compressed head- 
waters-form, which, farther down, changes into a more swollen 
form. I have, arbitrarily, decided to call specimens with the diameter 
less than 50 per cent. of the length by this name. 
This form is found in Powell, Clinch, and Holston rivers, in the 
upper parts. In the Powell, from Union Co., Tenn., up to Olinger, 
Lee Co., Va. (also in Puckell Creek, Lee Co.) ; in the Clinch from 
Anderson Co., Tenn., up to Clinchport, Scott Co., Va.;in the Holston 
