154 THOMAS SAY FOUNDATION 
PLATE 15 
FIGURES 188-189 
188 Perla hastata Banks 
Mottled areas on head; huge maxillae; rather square pronotum; 
color olivaceous; slender legs; no gills. 
189 Perla verticalis Banks 
Huge maxillae; somewhat square pronotum; no gills; pro- and 
mesonotum yellow in center and blackish all around. 
