ILLInots NATURAL Hisrory SurvEY BULLETIN 
PERIDIUS 
102 
JOCOSA 
105 
AMICA 
107 
ANCEPS 
PUNCTATA 
10 
i 
Fig. 97.—Brachycercus lacustris, fore wing. 
Fig. 98.—Tricorythodes atratus, fore wing. 
Fig. 99.—Tricorythodes peridius, male geni- 
Fig. 100.—Tricorythodes atratus, male geni- 
Fig. 101.—Tricorythodes stygiatus, male 
genitalia. 
Fig. 102—Caenis jocosa, penis lobes. 
Fig. 103.—Caenis forcipata, penis lobes. 
ATRATU 
103 
FORCIPATA 
8 
LATIPENNIS 
RIDENS 
Vol. 26, Art. 1 
STYGIATUS 
10 
GIGAS 
106 
SIMULANS 
12 
4 
109 
HILARIS 
DIMINUTA 
Fig. 104.—Caenis gigas, penis lobes. 
Fig. 105.—Caenis amica, penis lobes. 
Fig. 106.—Caenis simulans, penis lobes. 
Fig. 107.—Caenis anceps, penis lobes. 
Fis. 108.—Caenis latipennis, male genitalia. 
(After McDunnough.) 
Fig. 109.—Caenis hilaris, penis lobes. 
Fig. 110.—Caenis punctata, penis lobes. 
Fig. 111.—Caenis ridens, penis lobes. 
Fig. 112—Caenis diminuta, penis lobes. 
