G660723~-171

CONCLUSIONS: According to the close simjlarity \n numbers of right and
left valves of Anodonta grandis and Lampsilis radiata silequoidea taken,
it can be assumed that the collected specim2ns represent a similar population
of whole unionids, that is, two shells represent one unionid organism.

As can be seen in the table, length of shell has little to do with
its relative abundance as have area or depth:area little importance in
determination of abundance oot eiprearsTeses There seems to be a trend toward
greater variation in length as the nummber of a species increases, but
this may simply be a sampling phenomenon.

The age distribution curves for the six most abundant, measured species
are skewed to the right, indicating more older members of the population
than young. The curve for Quadrula quadrula is fairly well centered,
perhaps because more live specimens were collected for thds species than
the others. However, Ligumia subrostrata's curve is almost perfectly centered,
but no live specimens were collected, Either these first four curves
indicate a normal distribution for the live population or, more probably,
the sampling factor --the character of the shell (resistance to erosion,
availability for transportation by the stream and depositional characteristics).
An absence of young members in the curve might also indicate that the young
unionids are more likely to bury themselves into the tottom of the stream
bed, thus making themselves unavailable for surface studies.

This was only the first step in correlating the actual living biome
with the resulting fossil assemblage. Futur2 studies would include digging
into the stream bed to provide a complete collection of allithe living unionids,
having first compared this population with unionid populations at different
points along the river course. Then a study of fossilized material in the
Wakarusa Val’ey would be made. Such excavations are proceeding on the Wakarusa

as the Army Corps of Engineers are straightening and diking the channel from