74 
Rowland M. Shelley 
major impoundments exist in the Deep River sub-basin, but Randleman 
and Howards Mill lakes were authorized for construction in the mid- 
1970s (Shelley 1972). Work may soon begin on the former, but the latter 
is considered economically unjustifiable for the foreseeable future. 
KEY TO PIEDMONT CAPE FEAR BASIN UNIONIDAE 
Two regional keys are pertinent to North Carolina’s Atlantic unio- 
nids, in addition to the continental publication by Burch (1975). That by 
Johnson (1970) to all southern Atlantic species is more detailed, but it is 
mechanically flawed and of limited utility. Fuller’s key (1971) to the 
Savannah River basin fauna is more useful but contains species absent 
from this state. The following key relies mostly on conchological fea- 
tures and was devised to facilitate determinations in any Piedmont 
North Carolina drainage when used in combination with the diagnoses 
and figures herein and in Johnson (1970). 
1. Valves with lateral teeth 2 
Without this character 11 
2. Left valve with small interdental projection 
Lasmigona subviridis (Conrad) 
Without this character 3 
3. Post-basal mantle margin (before or ventral to incurrent 
aperture) with caruncle . . . Carunculina pulla (Conrad) 
Caruncle absent 4 
4. Post-basal mantle margin with ribbon-like flap of tissue .... 
Lampsilis cariosa (Say) 
Without this character 5 
5. Mantle and viscera pink or reddish in color 
Fusconaia masoni (Conrad) 
Mantle and viscera white or cream colored 6 
6. Shells sexually dimorphic, females swollen ventrad to accom- 
modate marsupium; post-basal margin with long papil- 
late projections 7 
Shells not sexually dimorphic; post-basal mantle margin not 
modified 8 
7. Valves small, periostracum dark green to black 
Villosa constricta (Conrad) 
Valves moderately-large, periostracum yellow 
Villosa delumbis (Conrad) 
8. Valves over three times as long as high 
Elliptio folliculata (Lea) 
Valves about twice as long as high 9 
9. Dendritic branchial papillae present 
Uniomerus tetralasmus (Say) 
Without this character 10 
