Neuse River Molluscs 
63 
Pulmonata: Planorbidae) was collected. We found this small planorbid 
on wood and macrophyte substrates in the littoral zone. Prior to 
our collection, G. deflectus had been reported from North Carolina 
only from Greenfield Lake, New Hanover County (Adams 1990), 
although Lenat (1983) reported an unidentified Gyraulus sp. from 
Cane Creek, Orange County, that could be this species. 
We encountered Musculium securis (Prime, 1852) (Bivalvia: 
Veneroida: Sphaeriidae) only in a narrow drainage ditch of a small 
pond in Wilson County, where it occurred in loose sediment among 
macrophytes. Adams et al. (1990) list M. securis as Undetermined 
status. Previously, Herrington (1962) reported this clam’s geographic 
distribution to include North Carolina, and Dawley (1965) examined 
specimens from Guilford County, North Carolina. 
Pisidium variable (Prime, 1851) was collected from Cattail Creek 
at SR 1738 in Johnston County, the first report of this peaclam in 
North Carolina. Previously, this species was considered to have a 
northern distribution, with Virginia and Tennessee being its most 
southern limit (Herrington 1962, Heard 1963). 
ACKNOWLEDGMENTS — We wish to acknowledge the follow- 
ing people for their assistance: William Adams for verification of 
snails and unionids, as well as for his professional advice, Gerald 
Mackie for identification of the sphaeriid clams, and Rowland Shelley 
for his assistance with the manuscript and his professional advice. 
Financial assistance has been received from the North Carolina 
Wildlife Resources Commission, Contract Number 92 SG 06. 
LITERATURE CITED 
Adams, W. F. 1990. Recent changes in the freshwater molluscan fauna 
of the Greenfield Lake basin, North Carolina. Brimleyana 16:103- 
117. 
Adams, W. F., J. M. Alderman, R. G. Biggins, A. G. Gerberich, E. P. 
Keferl, H. J. Porter, and A. S. Van Devender. 1990. A report on 
the conservation status of North Carolina’s freshwater and terrestrial 
molluscan fauna. The Scientific Council on Freshwater and Terres- 
trial Mollusks. 
Basch, P. F. 1963. A review of the recent freshwater limpet snails of 
North America (Mollusca: Pulmonata). Bulletin of the Museum of 
Comparative Zoology, Harvard University 129:399-461. 
Burch. J. B. 1973. Biota of freshwater ecosystems, identification manual 
no. 11, freshwater Unionacean clams (Mollusca: Pelecypoda) of North 
America. Environmental Protection Agency. W74-00564. PB 224 831. 
Burch, J. B. 1982. Freshwater snails (Mollusca: Gastropoda) of North 
America. Environmental Protection Agency. EPA- 23: 600/3-82-026. 
