EXPLANATION OF THE PLATES. 
PLATE XXI. 
FIG. 
1, Part of the interior of Cossus ligniperda. (Lyonnet.) 
a,b. The spinal chord and its ganglions. d. The bron- 
chize connected with the trachea. 
. One of the labial palpi of ditto. (Ibid.) 
. Another view of the interior of ditto. (Ibid.) a. Trachea. 
6. Bronchiz. c. Gisophagus. d. Ventricle or stomach. 
e. The lower intestines. ff. The bile vessels. g. Se- 
yicterium, or silk reservoir. h. Scalisterium, or saliva 
vessel. 
4. Part of one of the trachez of ditto, to show its coats and 
spiral thread. (Ibid.) Voc. IV. p. 62. 
. A portion of the interior of ditto, to show the epiploon, 
or fat. (Ibid.) aa. Epiploon. Vou. IV. p. 144. 
. Leg of ditto laid open. (Ibid.) aaa. Semipenniforn 
muscles of ditto. 6. Their lower point of insertion in 
the claw. c. Muscles of the coxa. Voc. IV. p. 178. 
7. Nervous system of the grub of Oryctes nasicornis. 
(Swamm.) a. The first ganglion or brain. c. The re- 
maining ganglions, forming a thick spinal chord. 
d, The nerves issuing from them. 
8. - of the louse. (Ibid.) «a. The brain. 
ccc. The ganglions. d. Nerves. 
9. The spinneret, or organ that renders the silk of the Cossus. 
(Lyonnet.) Vor. IIT. p. 124. 
os 3 
or 
op) 
* Vor. IV. Lerrers XXXVIL and XL. 
