195 
HyYMENARCYS NERVOSA Say 
Pentatoma nervosa Say, Descrip. n.sp. Heter. Hemip. N. A., 1831; Compl. 
Writ. Ent. N. A., Vol. 1, p. 321. 
The range of this species is about the same as that of the preceding 
one, but it has been taken in Canada. Our collection contains specimens 
from numerous localities in southern and central Illinois, but none from 
northern Illinois. The nymphal dates are June 21 and 22 and July 17. 
Imagines have been taken from March to December, the occurrences 
being quite uniformly distributed through the period. Cotton is recorded 
as a food plant. 
20. CoENus Dall. 
CoENUS DELIUS Say 
Pentatoma delia Say, Descrip. n.sp. Heter. Hemip. N. A., 1831; Compl. 
Writ. Ent. N. A., Vol. 1, p. 320. - 
This common species is widely distributed from Quebec to Van- 
couver, south to Florida and Texas, but is not numerous, and as Van 
Duzee says, is “apparently precinctive.’’ Our collection shows numerous 
records for northern and central Illinois, but only one, Dubois, for south- 
ern Illinois, indicating that it is at least rare in the Ozarkian-faunal dis- 
trict. Our nymphs were taken in June and July. The imagines were 
taken in every month from February to November, most abundantly, not 
in the summer months but in May and September. Olsen has kept 
imagines alive by feeding them on moth mullein (Verbascum blattaria). 
Subfamily ACANTHOSOMINAE * 
There are but two genera of this subfamily recorded from North 
America. We have both genera represented in our collections. 
The generic key which follows is based upon characters of the two 
species before me, and may not be serviceable in separating the other 
species. 
Key To GENERA 
Pronotum slightly but distinctly produced posteriorly on caudal margin laterad 
of base of scutellum, not forming an angle from basal line to lateral angle 
of pronotum; osteole short and broad, not extending more than midway to 
margin of metathorax; basal genital plates of female much longer than broad, 
IOS UAOM LOM EY te er tommer ere hile meter sensi acc ty hh oeete a cowieiee ane Meadorus lateralis. 
Pronotum not produced caudad laterad of base of scutellum, forming a straight 
line from base to lateral angle of pronotum; osteole long and narrow, extend- 
ing over two-thirds of the distance to margin of metathorax; basal genital 
plates of female as long as broad, subtriangular..... Elasmostethus cruciatus. 
MEADORUS LATERALIS Say 
Edessa lateralis Say, Descrip. n.sp. Heter. Hemip. N. A., 1831; Compl. 
Writ. Ent. N. A., Vol. 1, p. 312. 
This species has not been found so far as I am aware in Illinois, but 
as we have specimens in our collections from Lake Superior and Minne- 
[* Treatment by editor.) 
