IOWA ACADEMY OP SCIENCES. 
37 
successful collecting of Mr. E. D. Ball, whose faithful, per- 
sistent efforts it is a pleasure to acknowledge here. During 
the summer of 1897 I spent a couple of weeks in the northwest- 
ern counties, primarily in the investigation of Hessian fly 
injuries, but availing myself of such opportunities as pre- 
sented to collect the Hemipfcera, and such collections at Rock 
Rapids, Little Rock, Storm Lake, Alta, Cherokee and Sioux 
City, in Iowa, and Sioux Falls, S. D., by myself, and at Little 
Rock by Mr. Ball, who gave especial attention to the jassidee 
of the prairie grasses, furnish a basis for the preliminary 
consideration of the hemipterous fauna of the region. 
It will be noted that nearly all the localities cited belong to 
the western slope and most of them to the formation peculiar 
to the Missouri valley. Little Rock is the most distant from 
the river, but its elevation and the numerous hills and ridges 
in the vicinity, bearing the sparse vegetation characteristic of 
the plains farther west, makes it faunally related to the more 
western localities. The lower levels and river valleys in all 
these localities present a fauna more like that of the rest of 
the state, as will be seen by comparison of complete lists, but 
the portion discussed particularly here is the part that belongs 
really to the plains region and which is extended into this 
area because of the conditions prevailing on the more elevated 
portions. 
Much more attention was given to jassidse than other 
groups, hence the great preponderance in this family. How- 
ever, for the region and the vegetation worked, this is a 
natural preponderence. 
HETEROPTERA. 
Homcemus bijugis Uhl., is an abundant species in the region, 
occuring in rank vegetation of lower levels, and while ranging 
eastward and in some cases becoming fairly common, it 
appears to be more particularly typical of the plains. 
Lioclerma belfragii Stab, reported in the last proceedings, has 
not been obtained in Iowa in any other point than Little Rock. 
Stal. gives its habitat as “America borealis, Illinois.” 
Peribahis 'piceus Dali. Two specimens of this species from 
Little Rock are the only representatives taken in Iowa. They 
belong to the boreal fauna, and it is worthy of mention that the 
only part of Iowa touched by the transition zone, according to 
Merriam, is the northwestern corner, where these occurred. 
