ON THE SCALE INSECT OF MULBERRY TREES. 
Ill 
in order to attach the insect-body tightly to the surface of the 
bark. On the front corners of the rectangular chitinous frame¬ 
work, lies a wide process of the same chitinous nature, while 
posterior to this framework is inserted the root of the four 
modified filamentous mouth parts. Interiorly from this root are 
projected two pairs of chitinous rods, of which one seems a part 
of modified mandibles and the other, that of modified maxillae. 
The three sides (anterior and lateral) of this concave space 
are somewhat swollen, and marked off from the rest of the body 
by a horseshoe-shaped line. 
There are two pairs of spiracles (Fig. 8, a, PL. I) one on 
the ventral side of the first segment, and the other on the 
same side of the third segment of the body. The former 
pair open on either side of a process, on which the modified 
mouth-parts are inserted. They are simple oval openings 
measuring 0,01 mm. in longer diameter. Round this opening, 
except on its posterior sides, there lies a hemispherical area 
marked with a number of round spaces having a few fine 
perforations (Fig. 8, PL. I.). These perforations seem to 
secrete sticky filaments, which lie always in a clustre over the 
spiracle in the form of a white mass. 
The second pair of spiracles are simple, small, and nearly 
circular openings, and they lie apart from each other on the 
ventral side of the third segment. They are smaller than those 
on the first segment, and measured 0,0073 mm. in diameter (Fig. 
8, a. PL. I.). 
The skin is pretty thick, transparent and strong, and there 
may be found a large number of very fine irregular transverse 
striations on the entire surface of the body except the pygidium, 
which is, on the contrary, marked with longitudinal striations. 
In addition to the striations, the body is covered with fine short 
hairs, which grow somewhat thicker near the periphery of the 
body. 
The average length and breadh of the female insects are 1,3 
mm. and 1,0 mm. respectively. 
The scale which covers the female insect is more or less 
round, oval, and flat, bearing a slightly projecting apex nearly at 
the anterior third ol the scale, and thus it takes the form ol a 
patella, whence the specific name “ patélliformis” is given. It 
