SCUTELLEROIDEA OF IOWA 9 
deed, the winters are colder and the summers hotter than for the 
same parallels near the eastern coast of the United States. Sud- 
den and marked changes in temperature are not uncommon and 
these probably serve as an effective barrier to the northward dis- 
persal of many of the less hardy southern forms. Then too, Iowa 
is just on the border line between fairly typical eastern and 
western conditions as well as between Transition and Lower Aus- 
tral so that the fauna is likely to be somewhat varied in its af- 
finities. In the western part of the state in particular, conditions 
begin to assume those of the Great Plains region and here one is 
at once struck with the intermediate character of the penta- 
tomid as well as other faunas. 
The appended table will serve to show in graphic form some- 
thing of the relation of the pentatomid faunas of Florida, New 
England and Nebraska to the fauna of Iowa. The basis of these 
records is taken from the published lists together with specimens 
received from the localities mentioned. In preparing the data 
for tabulation the nomenclature has been made to conform to the 
system employed in this paper in order that a uniform basis for 
comparison may be obtained. 
Genera Genera com- Species and sub- Species and sub- 
in list mon to Iowa _ species in list species common 
to Iowa 
Iowa 33 aid 63 ae 
Florida 44 23 80 30 
New England 36 31 59 46 
Nebraska 35 30 68 50 
Until recently little has been done on the group Scutelleroidea 
in Iowa outside the lists and a few notes by Professor Herbert 
Osborn. During the past four or five years the writer has been 
collecting material and issuing brief progress reports in the way 
of distributional and ecological notes from time to time. 
All of Osborn’s notes on Iowa pentatomids were published in 
the Proceedings of the Iowa Academy of Sciences and the dates, 
together with brief summaries of his papers are herewith 
appended in chronological order so that the historical setting of 
this work may be brought to mind. 
Proc. Ia. Acad. Sci. for 1888, Vol. I, 1890, page 49, Herbert 
Osborn, ‘‘The Hemipterous Fauna of Iowa’’ (Abstract). In 
