202 
ern Illinois; and we have it from Havana and Carbondale in Illinois, July 
31, October 5, and December 13. 
The ground-color is black, marked with red or orange. The scutellar 
mark is V-shaped; the costal margin is narrowly pale; the pronotum is 
black, with red median line and front and side border connecting with 
the scutellar mark. 
6. ZicronA A. &S. 
ZICRONA CAERULEA Linn. 
Cimex caeruleus Linné, Syst. Nat., ed. 10, Vol. 1, p. 445. 1758. 
This beautiful metallic greenish, purplish, or bronzy black species 
may occur in Illinois. Although a western form, ranging from Idaho to 
New Mexico and California, it has been reported from Mt. Washington, 
N. H., and we have it from Michigan (Nason), identified by Osborn as 
the variety cuprea; but the color is purplish rather than bronzy. 
7. RHACOGNATHUS Fieb. 
RHACOGNATHUS AMERICANUS Stal 
Rhacognathus americanus Stal, Enum. Hemip., Pt. 1, p. 33. 1870. 
A rare species, listed only from Winnipeg (Can.), Illinois, and Ohio, 
The Bolter Collection contains five examples from northern Illinois. 
Family CYDNIDAE 
Key To SUBFAMILIES 
‘ 
NYMPHS 
Spiracles not included in the lateral plate, the two setae obliquely or trans- 
versely placed behind it, forming a triangle; mediodorsal plates of scent- 
PLANS <GUStiM Ch: cyccuerarie tole ake oie resanes stones Prcarialeleporde crate er staterer Rene hevaRets eee aarti CYDNINAE. 
Spiracles and their setae included in the lateral plate, the three nearly a 
straight line; mediodorsal plates of scent-glands with at least the first and 
second yeonfluentes Hee 5 ie PAN ee aR aa THYREOCORINAE. 
IMAGINES 
Scutellum of moderate size, subtriangular, not reaching tip of abdomen, frena 
long; corium exposed, broadly triangular; hind wing lobes about equal, sepa- 
Tatedapy Slallows WOUGHES aeiateece coatereiels icye males arehedatn sincenaleketeeesemene leienetens CYDNINAE. 
Scutellum very large, covering abdomen to apex, frena short; corium largely 
membranous, the exposed opaque part narrow; hind wing lobes deeply incised, 
the second large and very prominent..........2.2-.cceeseseuns THYREOCORINAE. 
Subfamily CYDNINAE 
Key To TRIBES 
NYMPHS 
Spiracular setae on segments 3-7 placed transversely *...........--... Sehirini. 
*T have not seen a nymph of this tribe; the character has merely been deduced 
by analogy from a comparative study of adults which in other species have this struc- 
ture the same as in the nymphs. 
