60 ItLinois NaturAt History Survey BULLETIN Vol. 26, Art. 1 
dorsal spines and seven to nine ventral One to three ventral spines on each penis 
spines, fig. 129.......19. fratercula lobe in basal area, fig. 145............ 
Penis lobes with at least one pair of apical, IS Spe ng. eeeee 21. rotunda 
submesal spines; each ie eee ng Se 23. dite lobes Shon Or eee 
31x sal spines in basal area S. a large, ventral, su ‘ 
fa aE “4h te 8 of ete eu 3 figs. 140, 141 es thou 22. prudentalis 
22. No ventral spines on penis lobes in basal Penis lobes lacking a ventral, subapical 
OFEE MMe LORE bite pete sis 20. invaria enlargement........ «29.5000 ane 24 
SUBVARIA 
: PRUDENTALIS 
PRUDENTALIS 
139 | LUTULENTA 
et 
688 eee 
142 
BICOLOR 
TEMPORALIS 
COXALIS 
Fig. 136.—Ephemerella subvaria, male genitalia. 
Fig. 137.—Ephemerella excrucians, male genitalia. 
Fig. 138.—E phemerella argo, male genitalia. 
Fig. 139.—Ephemerella lutulenta, male genitalia. 
Fig. 140—Ephemerella prudentalis, lateral aspect of male genitalia. (After McDunnough. ) 
Fis. 141.—Ephemerella prudentalis, dorsal aspect of male genitalia. (After McDunnough.) 
Fig. 142.—E phemerella bicolor, male genitalia. 
Fig. 143.—Ephemerella temporalis, male genitalia. 
Fig. 144—Ephemerella coxalis, male genitalia. (After McDunnough.) 
