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 

 month-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 of the scale, and thus it takes the form of a 

 patella, whence the specific name " patcllifovmis'" is given. It 



