6 IOWA STUDIES IN NATURAL HISTORY 
Suborder HETEROPTERA Latreille 
About two-thirds of the total number of Hemiptera are Heter- 
optera and in North America in the neighborhood of 1500 species 
have been described. 
Series POLYNEURIA Reuter 
In the classification adopted by Reuter, seven ‘series are rec- 
ognized as making up the Heteroptera. By thus breaking up that 
suborder, the affinities of the families are made more apparent 
since it is evident that all the forms contained in the old series 
Gymnocerata, of which the Scutelleroidea formed a part, were 
not genetically related. The series Polyneuria in which the 
superfamily Seutelleroidea is now placed may be diagnosed 
briefly as follows: 
Head never transversely impressed before the eyes; antennae longer, 
usually much longer than the head; beak usually of four segments, rarely 
with three, in which case the last two segments are confluent. Pectus never 
composite. Meso- and metasterna simple. Hemelytra provided with a clavus 
ecorium and membrane; membrane with many veins, seldom with few veins. 
Ventral abdominal stigmata two to seven. Coxae rotatory. Tarsal claws 
provided with arolia. Eggs operculate; micropyles not parietal; embryo 
provided with an apparatus on the occipital portion of the head for break- 
ing the operculum of the egg. 
Superfamily SCUTELLEROIDEA (Burmeister) 
Head very often distinctly clypeate or shield-shaped; ocelli usually pres- 
ent; antennae usually of five segments, rarely of three, four, or more than 
five; antenniferous tubercles within the lateral margins of the head; anten- 
niferous spine seldom developed on head. Scutellum large or very large, 
usually at least reaching middle of abdomen, the apex often covering the 
interior basal angle of the membrane, sometimes covering the entire dorsal 
surface of the abdomen. Clavus m the macropterous forms attenuate at 
apex forming no commissure or a very short one (Urolabidae) internally 
behind the apex of the scutellum; membrane usually with numerous veins, 
sometimes anastomosing, rarely with few veins, in which case the seutellum 
is large. 
This group of the Heteroptera consists, for the most part, of 
large and fine appearing species which are quite easily seen and 
as easily captured. The members of the superfamily are prac- 
tically cosmopolitan in distribution but are more characteristic 
