68 
Rowland M. Shelley 
reaches of the Haw and Deep rivers, which join along the Chatham-Lee 
counties line to form the Cape Fear River proper. Sampling of the live 
individuals and empty valves on the banks took place at public access 
points, and smaller creeks were waded for most of their lengths. In addi- 
tion, Dr. Charlotte Dawley donated to the State Museum her collection 
of mollusks, most of which came from headwater areas of the Haw 
River in Guilford County and formed the basis for her checklist (1965). 
Thus her material plus mine spans the upper part of the basin, and this 
contribution supplements the works of Walter and Clarke in detailing 
the unionid fauna of central North Carolina. For the sake of comple- 
tion, I include records and species from the lower or Coastal Plain sec- 
tion of the basin and also summarize reports from other North Carolina 
drainages. The paper concludes with a discussion and comparison 
(Table 1) of the faunas of the Tar, Neuse, and Cape Fear basins, the 
three major drainages located wholly within the state. 
THE CAPE FEAR RIVER BASIN 1 
The Cape Fear River basin, the largest wholly within North Caro- 
lina, drains about 18% of the state (14,624 km 2 ) and all or part of 26 
counties (Fig. 1,2). The basin is roughly 322 km long by a maximum of 
96 km wide, extending from northwest of Greensboro to southeast of 
Wilmington. About 6 billion gallons of water a day flow into the Atlan- 
tic Ocean through the Cape Fear estuary, the only major one in North 
Carolina with direct access to the sea. Three locks and dams in Bladen 
County control flow of the Cape Fear River, and tidal influences are felt 
to the lowest of these, approximately 59 river km above Wilmington or 
just above site L (Fig. 2). The upper third of the watershed is in the 
Piedmont Plateau Physiographic Province and is characterized by 
undulating terrain with relatively deep valleys and narrow flood plains. 
Most of the basin, however, lies in the Sandhills and Coastal Plain prov- 
inces, where flat terrain causes relatively sluggish streams. Between the 
Piedmont Plateau and Coastal Plain is the Fall Zone, so named because 
of the small, discontinous rapids formed as water passes from the con- 
solidated rock substrates of the Piedmont onto the unconsolidated sed- 
iments of the Coastal Plain. Elevations in the basin range from mean 
sea level to 90 to 120 m in the Fall Zone to around 300 m in the 
headwaters. 
The Cape Fear River begins on the inner edge of the Fall Zone 
near the town of Moncure, and the area of study was entirely in the 
Haw and Deep river sub-basins, of which the former, draining an area 
of 2,712 km 2 , is slightly larger. This sub-basin is about 1 12 km long and 
1 All information in this section is from the 1983 report titled “Status of Water 
Resources in the Cape Fear River Basin,” North Carolina Department of Natu- 
ral Resources and Community Development, Raleigh. 
