1985] 
Schmidt & Tarter — Acroneuria carolinensis 
401 
b 
Head Width r mm 
Figure 3. Growth rates of Acroneuria carolinensis naiads from Panther Creek, 
Nicholas County, West Virginia, 1983-1984: a) frequency of size classes; b) trendline 
of the population, calculated by gliding means over five successive size-class frequen- 
cies at a time; c) periodicity of maximum frequency of size. 
m from the water surface. They were found clinging to sand, rocks, 
rhododendron stems and moss. Based on the number of exuviae 
collected (33), peak emergence was on 8 June 1984; emergence 
lasted three weeks. The first exuvium was collected on 1 June and 
the last on 16 June. Emergence peaked with a corresponding peak in 
