62 IOWA STUDIES IN NATURAL HISTORY 
In accordance with my delimitation of this form I have in- 
cluded here specimens which average somewhat smaller than 
the preceding and in which the vaginal plate of the female is 
triangular rather than quadrate. The general coloration in the 
present form is a somewhat reddish yellow; however, none of 
my Douglas Lake specimens are as dark as some from Oregon, 
which are in my collection. As between the two representatives 
of the genus found at Douglas Lake, the present form has the 
humeri somewhat less attenuate than in A. cynicus, although 
the humeri of both are about equally acute. All my specimens 
of A. bracteatus have the anterior pronotal margins more 
strongly crenulate than in A. cynicus. 
Podisus maculiventris (Say) 
At no time during our stay at Douglas Lake was this bug 
common, although in most places in the United States and 
Canada it is the most abundant member of the genus. Adults 
are likely to be met with after the middle of July in low grassy 
places such as lake borders and bogs. I took several along the 
shore of Lancaster Lake on July 20, at which time also a num- 
ber of nymphs in third and fourth instars were secured. Several 
times I have taken the species from willow (Saliz). I have 
four specimens that were taken in beach drift near the Biolo- 
gical Station. 
P. maculiventris may be separated from the following species 
by its larger size (10.0—14.0 mm.), and the proportionately 
longer ventral spine which extends forward between the pos- 
terior coxe. 
Podisus modestus (Dallas) 
This is the smallest representative of the subfamily in the 
region, averaging in length from 7.0 to 10.0 mm. It is also a 
little paler than the preceding form and shares with it the 
distinction of having the wing membrane marked by a longitu- 
dinal brownish vitta. I have but eight specimens, all but one 
of which were taken after the middle of July. One adult was 
taken in beach drift on July 11. 
Podisus placidus (Uhler) 
So far as the Douglas Lake region is concerned this seems 
to be the commonest representative of the genus and during 
