56 IOWA STUDIES IN NATURAL HISTORY 
mid-August. If the season is very dry, as often happens in the 
region, the numbers become much reduced. 
The species also visits the sumach frequently, although not in 
such great numbers as E. euschistoides, but I have never seen it 
feeding upon this plant. 
In the Station records for 1918, I find this form recorded on 
Salix by Hussey. 
In this region this is the only member of the genus in which 
the venter is furnished with a row of black spots, which may 
be, in some eases, more or less obsolete. 
Euschistus variolarius (P. B.) 
While in Iowa, and, indeed, in most parts of the United 
States where the three species of Euschistus here mentioned 
occur, this is the most common representative of the genus, but 
two specimens are in my collection from Douglas Lake. I have 
seen but one other and that in a student’s collection; it was 
taken on July 2 from grass growing along the east shore of 
Douglas Lake. My own specimens, both males, were taken July 
15 and 16, 1920, in beach drift. 
This species is to be distinguished from E. euschistoides, its 
nearest ally in the Douglas Lake fauna, by the absence of black 
points at the incisures on the edges of the abdomen, the usually 
rounded anterior margin of the head and the rounded median 
black spot on the genital segment of the male. 
Coenus delius (Say) 
Although this is a widely distributed and, in some parts of 
the United States at least, a fairly common species, it is one of 
the less familiar forms in the Douglas Lake region. The net 
result of our two seasons of collecting is but four adult in 
dividuals along with a number of nymphs. More of the latter 
might have been secured, but all the adults that were seen were 
taken. 
Apparently this is one of the species which matures com- 
paratively late in the season. My earliest record for an adult is 
July 7. Most of the nymphs were taken about the middle of 
July; one in the second instar was taken July 11, while another 
in the fourth instar was taken July 14. On July 17 an adult 
was taken in which the exoskeleton was still soft and yellowish, 
