362 
Psyche 
[Vol. 92 
e=iE 
"7^ 
— 2 
L 4— 1 
» i 1 
" i_4 
r i 
1 c 
: t— 4~ 
s 
c, L=£= 
> 1 
- i — 1 — i 
-I— 1 
52 PP 
f— | 
5 1 | i 
— 2 
CO 1 — . 
1( 
7 
f 
n 
1 
O 
I I I I l«| I I I I I I I I U I I I I II I I k| I I I I I I I I l°| 
mm l H<P!M P D9 H 
Figure 3. Population range diagram showing monthly head width variations of Baetisca Carolina nymphs from Panther 
Creek, Nicholas County, West Virginia. Vertical lines = range, horizontal lines = mean, open rectangle = two standard errors 
of the mean, f = female, and m = male. 
