May, 1953 
meee 
13 
15 
23 
25 
Fig. 11—Caenis simulans, hind leg of adult 
male. 
Fig. 12.—Brachycercus lacustris, hind leg of 
adult male. 
Fig. 13.—Tricorythodes atratus, hind leg of 
adult male. 
Fig. 14.—Neoephemera purpurea, hind leg of 
adult male. 
Fig. 15.—Callibaetis fluctuans, hind leg of 
adult male. 
Fig. 16.—Ephemerella needhami, hind leg 
of adult male. 
Fig. 17.—Stenonema pulchellum, hind leg of 
adult male. 
Fig. 18—IJsonychia sicca, hind leg of adult 
male. 
Burks: THE Mayr tiers oF ILLINOIS 
ns 
24 
26 
Fig. 19.—Heptagenia sp., hind leg of adult 
female. 
Fig. 20.—Siphlonurus alternatus, hind leg 
of adult female. 
Fig. 21.—Leptophlebia nebulosa, hind leg of 
adult male. 
Fig. 22.—Siphloplecton interlineatum, hind 
lez of adult male. 
Fig. 23.—Ephoron leukon, fore leg of adult 
male. 
Fig. 24.—Ephemera simulans, 
adult male. 
Fig 25.—Siphloplecton 
leg of mature nymph. 
Fig. 26.—Ameletus 
mature nymph. 
fore leg of 
interlineatum, hind 
hind 
lineatus, leg of 
