1923. ] Anatomy and Bionomics of Red Cotton Bug. 27 
are seen in the mid-dorsal line of the abdomen. They are in the 
intersegmental membrane of segments 3/4, 4/5, 5/6. 
In both sexes, the anterior half of the notum of segment 
I (Fig. 3) is thickly beset with long hairs, and the posterior 
margin of V is produced backwards into a lobe to fit in a notch 
on the anterior margin of the notum of segment VI. The sub- 
sequent segments have deviated from the simple form above 
described, being modified differently in the two sexes. To make 
this clear a separate description of the male and the female 
is given below :— 
Male (Figs. 3a, 4a, 10a).—Segment VII is the hindermost 
of the visible segments. Its notum is produced backwards 
into a large blunt lobe covering the posterior chamber of the 
terminal segment. Segments VIII-X are telescoped into one 
another to form a pear-shaped organ, the major portion of 
which remains retracted in VII. Segment VIII appears dor- 
sally as a transverse band, which widens down laterally to 
meet the broad trough-shaped ventral part. Segment IX re- 
sembles a hollow pear-shaped body whose upper surface has 
sunk down to meet the ventral surface in front and behind, 
leaving between a narrow transverse band. Consequently 
this segment is divided into two chambers, the small anterior 
and the spoon-shaped posterior or terminal (Sharp), separated 
by downwardly defiected double wall, called the diaphragm 
The rectum and genital duct pass through this diaphragm to 
open externally in the terminal chamber. Segment X is small, 
ringlike and surrounds the anus in the terminal chamber. 
al cerci are absent. The genital duct terminates in 
a chitinous copulating organ termed oedeagus (Sharp) situated 
in the terminal chamber. The oedeagus usually remains con- 
cealed under the rectum. It is surrounded by a thick chitin- 
Ous coat termed theca, and its wall is strengthened by four 
thick chitinous pieces, two of which are pointed and curved at 
their ends (OF. §. Fig. 10d), Lateral to the oedeagus lie two 
terminal chamber; they are probably the homologues of the 
consists above of a narrow transverse : 
attached broad ventral plates (due to the fission of the sternal 
portion) which are thickly covered with bristles and enclose 
