108 
William F. Adams 
The genus Liogyrus Gill, 1863, is now considered a subgenus of 
Amnicola Gould, 1841 (Burch 1982). 
Bivalvia 
Johnson (1970) synonymized Elliptio fisheriana (Lea, 1838) with E. 
lanceolata (Lea, 1828). Davis (1984) determined that E. fisheriana was 
distinct from E. lanceolata and that E. folliculata (Lea, 1838) and E. 
producta (Conrad, 1836), which had also been synonymized with E. 
lanceolata by Johnson (1970), were also distinct from it and from each 
other. Johnson (1984) synonymized E. producta with E. angustata (Lea, 
1831). The ranges of these species are uncertain, and which species 
occurred historically in Greenfield Lake is unknown. 
Uniomerus tetralasmus (Say, 1831) is still a valid species, but south 
Atlantic drainage Uniomerus are now considered to be U. obesus (Lea, 
183 1) (Johnson 1984). 
Johnson (1970) synonymized Anodonta teres with A. cataracta and 
Villosa vaughaniana with V. delumbus. However, Anodonta teres and 
Villosa vaughaniana are still regarded as distinct by some researchers 
(e.g. Porter 1985, Turgeon et al. 1988). 
The genus Limosina Clession, 1872, is synonymous with Eupera 
Bourguignat, 1877 (Heard 1965). Eupera cubensis (Prime, 1865) and 
Musculium transversum (Say, 1829) are still considered to be valid 
names. 
METHODS 
All of the major tributaries, the nearshore lake bottom out to a 
distance of about 10 m, and the creek downstream of the dam were 
sampled between January 1984 and October 1987. Eighteen stations 
were investigated and are shown in Fig. 1. During January 1984 and 
again in January 1986, the lake was drained for several weeks, and the 
substrate for 6-30 m from the bank was exposed. This permitted 
thorough searches, although some mollusks may have retreated with the 
receding water. Because movements of unionids during such events have 
been shown to be random (Samad and Stanley 1986), the species 
obtained are considered to be representative. The central portions of the 
lake could not be sampled, as soft sediments and deep water made 
collecting by the methods used impossible. Summer collections of 
gastropods were made by sweeping a fine-mesh net through floating 
aquatic macrophytes, by raking mats of submerged aquatic macrophytes, 
and by hand. The creek below the dam was sampled by hand and by 
raking during low tides in summer 1985 and during the winter drawdown. 
Approximately 40 man-hours were spent in collecting. 
