Unionid Mollusks 
75 
10. Post-basal mantle margin heavily pigmented; periostra- 
cum dull Elliptio complanata (Lightfoot) 
Post-basal mantle margin not heavily pigmented; periostra- 
cum glossy Elliptio raveneli (Conrad) 
11. Valves without pseudocardinal teeth 12 
Valves with prominent or vestigial pseudocardinal teeth .... 13 
12. Umbos extending above dorsal margin 
Anodonta cataracta (Say) 
Umbos flat, not protruding above dorsal margin 
Anodonta imbecilis (Say) 
13. Pseudocardinal teeth slight, barely detectable 
Strophitus undulatus (Say) 
Pseudocardinal teeth prominent 14 
14. Posterior slope corrugated, with radial undulations or wrin- 
kles; umbos relatively low 
Alasmidonta varicosa (Lamarck) 
Posterior slope smooth; umbos high, inflated 
Alasmidonta undulata (Say) 
SPECIES COMPOSITION 
Unionid species collected in the upper Cape Fear system are listed 
below along with synonyms that have been used to refer to North Caro- 
lina records. Localities refer to symbols in Figure 2. Previous North 
Carolina records from the Cape Fear and other drainages, observations 
on preferred habitat, and the statewide conservation status reported by 
Fuller (1977) are variously included under “remarks.” Subfamilies and 
tribes follow the arrangement of Burch (1975). 
Subfamily Amleminae 
Fusconaia masoni (Conrad 1834) [= Pleurobema brimleyi (Wright) 
(Walter 1956); Elliptio merus (Lea) (Dawley 1965); and Pleuro- 
bema (Lexingtonia) masoni (Conrad) (Johnson 1970)] — Fig. 3. 
Diagnosis'. Valves rhomboidal in outline; mantle and viscera pink or 
reddish in color. 
Localities'. 19, I. 
Remarks'. Walter (1956) encountered F. masoni below dams in tributar- 
ies of the Neuse River near Raleigh, and Clarke (1983) found it at 13 
stations throughout the length of the Tar River. Johnson (1970) cited 
specific localities in the Roanoke, Tar-Pamlico, Neuse, Yadkin, and 
Catawba systms but recorded the Cape Fear River without further data. 
Fuller (1973) placed this species in the genus Fusconaia on anatomical 
grounds and reported it from the Coastal Plain section of the Cape Fear 
River at site I. Fuller (1977) alluded to its occurrence in the Rocky 
River and assigned F. masoni to “Threatened” status in North Carolina. 
