May, 1953 Burks: THE Mayr ies oF ILLINOIS 83 
194C 
I96C 
Shue dese ty 
Mboy MN TPARP ACN DOR 
Any ibe es AN Mut! ; 
iJ ay 
Fig. 1934 .—Leptophlebia sp., gill of fifth abdominal segment. 
Fig. 193B.—Leptophlebia sp., gill of first abdominal segment. 
Fig. 193C.—Leptophiebia sp., gill of seventh abdominal segment. 
Fig. 1944 —Paraleptophicbia praepedita, gill of fifth abdominal segment. 
Fig. 194B.—Paraleptophlebia praepedita, gill of first abdominal segment. 
Fig. 194C.—Paraleptophlebia praepedita, gill of seventh abdominal segment. 
Fig. 1954 .—Choroterpes basalis, gill of fifth abdominal segment. 
Fig. 195B.—Choroterpes basalis, gill of first abdominal segment. 
Fig. 195C.—Choroterpes basalis, gill of seventh abdominal segment. 
Fig. 196A .—Habrophlebia vibrans, gill of fifth abdominal segment. 
Fig. 196B.—Habrophlebia vibrans, gill of first abdominal segment. 
Fig. 196C.—Habrophlebia vibrans, gill of seventh abdominal segment. 
Fig. 197.—Paraleptophlebia praepedita, nymphal labrum, dorsal aspect. 
Fig. 198.—Habro phiebiodes americana, nymphal labrum, dorsal aspect. 
