164 THOMAS SAY FOUNDATION 
PLATE 20 
FIGURES 197-198 
197 JIsoperla petersoni Claassen 
Wing pads lacking or very short; wide median yellow stripe with a 
narrower yellow stripe each side of the abdomen. 
198 Isoperla signata Banks 
Yellow pronotum, bordered with black; yellow spot between hind 
ocelli; banded abdomen. 
