May, 1953 Burks: THE Mayr iss or ILLINoIs 59 
of our knowledge of the species in the genus 
Ephemerella, this female type specimen of 
quebecensis cannot be placed even to species 
group. Specific characters for the females 
of this genus have not yet been found. 
KEY TO SPECIES 
Aputt Ma tes 
1. Third segment of genital forceps long and 
slender: six times as long as broad, 
TAB ee cree. rag ave, Sc 33. attenuata 
Third segment of genital forceps shorter 
and more stout: never more than four 
times as long as broad, usually as 
broad as long, figs. 118, 122, 123, 136, 
LS ihe gOS oS a ee 2 
2. Third segment of forceps three or four 
times as long as broad, figs. 118-122. .3 
Third segment of forceps less than twice 
as long as broad, sometimes only as 
long as broad, figs. 123, 124, 126-138. .7 
Second segment of forceps relatively short 
and subangulate, with a sharp and deep 
mesal constriction, fig. 122...1. lata 
Second segment of forceps relatively long 
and more evenly curved, not having a 
sharp and deep mesal constriction, 
AI RGE INO abil t isl was A: sto) = ce craye Ghe e a- os + 
4. Outer surface of hind femur with numer- 
Guspsmalle black dots: ..... os..%.. 5 
Outer surface of hind femur without black 
ios) 
5. An arcuate, transverse row of four black 
dots present on each abdominal sternite 
ole Ste, thee 2. tuberculata 
Abdominal sternites without transverse 
rows of black dots ...... 3. walkeri 
6. Second segment of forceps only three 
times as long as basal segment, fig. 121; 
fore wing only 6-7 mm. long......... 
eer Pas 2. ce 4. cornutella 
Second segment of forceps four times as 
long as basal segment, fig. 120; fore 
wanes 9mm: long... ..-:. 5. cornuta 
7. Penis lobes broadened near apexes and 
bearing a pair of subapical, lateral 
tubercles, figs. 123, 124, 126......... 8 
Penis lobes not broadened near apexes 
and not bearing a pair of subapical, 
lateral tubercles; either not expanded 
near apexes, or, if so, bearing several 
dorsal or ventral spines, figs. 132, 135- 
Us © Sol UR a eee 12 
8. Abdominal tergites 2-7 white (in freshly 
killed specimens), with a pair of small, 
brown, lateral dots or streaks on each 
(ELOUICS aoe Aa a 6. frisoni 
Abdominal tergites tan or brown....... 9 
9. Caudal filaments white, with articulations 
MOtsdankened 4.75 fess. 3. 7. sordida 
Caudal filaments with at least basal 
articulations darkened with red or 
RREWRE PRE: = WR MS re LRN. os 10 
10. An arcuate, transverse row of four black 
dots present on each abdominal sternite 
+: Rca eRe eee 9. serratoides 
Abdominal sternites without transverse 
fowarnt black dots.) 26... ..2c..+. 11 
it 
13. 
iS: 
18. 
21. 
Genital forceps strongly bowed, fig. 128; 
abdominal sternites light tan, with dark 
brown, longitudinal streaks near each 
laterallmarcines: «een 8. serrata 
Genital forceps more nearly straight, fig. 
133; abdominal sternites uniformly 
shaded with tan, lacking lateral, dark 
brown, longitudinal streaks.......... 
GPaisd RO RE 10. deficiens 
Penis lobes with a deep, median, apical 
notch, lateral margins projected pos- 
teriorly as relatively narrow processes, 
as in figs. 130-132, 134-138, 145... .13 
Penis lobes with only a very shallow, 
median, apical notch, lateral margins 
not produced posteriorly, figs. 139-144, 
146-150; penis lobes never bearing 
SLOIMEISPINES icles ston es ie pene 23 
Penis lobes entirely without spines, fig. 
131; upper face red-brown, with area 
below antennae bright yellow........ 
D teed ERE SS Rae 11. needhami 
Penis lobes provided with spines, as in 
HES LSOM1G2 O34 18 8h ace ae ee 14 
Penis lobes divided on meson to level of 
bases of genital forceps; numerous, 
minute spines borne by mesal surface 
of each penis lobe, fig. 130.......... 
rd Stele Leh Re ae 12. aurivillii 
Penis lobes not divided on meson to level 
of bases of forceps; penis lobes bearing 
relatively few, large spines, figs. 132, 
Lateral processes of penis lobes long and 
slender, extended straight, fig. 134... . 
BR oa ees 13. septentrionalis 
Lateral processes of penis lobes short, 
curved inward at apexes, figs. 132, 
LB5=L3 Sieve tees shir c ec eee ee 16 
Second segment of genital forceps not 
suddenly swollen at apex, figs. 127, 137, 
iy: aera eteern <1 one tie, eect one he ib7/ 
Second segment of genital forceps sudden- 
ly swollen at apex, figs. 129, 132, 135, 
D366 14S: igor Rey he etn eT 19 
Penis lobes short and broad, with each 
lobe bearing two or three dorsal spines, 
three or four ventral spines, and two 
or three apical spines, fig. 138........ 
Nias WAL Sys Let MA ane Ce tae 14. argo 
Penis lobes narrower and more elongate, 
with spines arranged differently, figs. 
QELS A SP eet ae ee Tia a ret 18 
Dorsum of thorax tan and yellow; com- 
pound eyes of living insect pinkish 
[oh c rae MP neee ete po ea: SNS 15. ora 
Dorsum of thorax deep reddish brown; 
compound eyes of living insect yellow 
alae Sea ee Oe eee phe 16. excrucians 
Caudal filaments entirely white, with 
articulations not darkened........... 
Saas Gi ee SO ee ae ete 17. dorothea 
Caudal filaments with at least basal 
articulations darkened............ 20 
Wings with veins brown... .18. subvaria 
Wings with veins and crossveins hyaline, 
or costal longitudinal veins faintly 
tinged with light yellow........... 21 
Penis lobes without apical, submesal 
spines; each lobe bearing two to three 
