694 MR. P. R. AWATI ON THE MECHANISM 
is covered dorsally with small hairs or papillz, and is very smooth 
ventrally. It is complementary in its function to the labium, 
i. €. it is applied closely against the labium to form the deep 
groove which keeps the stylets in place and prevents their lateral 
movement (text-fig. 9, Lbr.). 
(4) The Maxillary Sclerite—This is situated laterally to the 
epicranium just below the eyes, and forms the lateral boundary 
of the mouth. As stated above, it is one of the parts of the em- 
bryonic maxilla. The protractors of the maxille areattached to it. 
(5) The Labiwm (text-figs. 1, 29, Lb.).—This structure consists 
of four segments. The first is broader and shorter and has 
practically no groove, or, if there is any, it is very shallow and 
flat. The first joint—i. e. the joint between the first and second 
segments—is swollen, and this swelling is due to a great develop- 
ment of chitinous ‘‘tendons” to which the labial muscles are 
Text-figure 2, 
7 (615 14:13 
21 Ch. V. Mee wae Ay keSies 
Nerve 
to G Gre 
Ph. 
V. Ph. 
Op. 
Chitinous rods 
in muscles 
Many, 
LUT 
MUN 
Mh 
UD 
ACT 
Wo 
“il 
LUT 
Gs. CV. Sub.G. 
Lygus pabulinus. 
Diagrammatic median longitudinal section. Ob. 3 & Oc. 4. 
The lines numbered 9 to 22 indicate the levels of the sections shown in the 
corresponding figures, 
N.B.—In all the sections the microscope tube is not drawn out to its 
proper length. 
For explanation of the lettering see p. 693. 
