EXPLANATION OF THE PLATES. 613 
FIG. 
12. Part of the trunk of Goerius olens, to show its antepectoral 
spiracle. Vol. IV. p. 43. 
13. Part of the abdomen of Pneumora. a. The series of 
ridges, by striking the hind leg over which they pro- 
bably produce their noise. Vol. II. p. 391 5 III. p. 339. 
14. Underside of part of the alitrunk of Lygceus sexmacu- 
latus K. MS. b. Branchiform apparatus between the 
scapula and parapleura. Vol. IV. p. 45. 
15. ■ . . ■ Pentatoma rufipes. 
a. Corrugated membrane, b. Apparent fringe of hairs 
or bristles. Ibid. 
1 6. Spiracle of larva of Oryctes nasicornis. (Sprengel.) 
17. ——— Dytiscus marginalis. (Ibid.) 
18. Part of the trachea and bronchiae of the pupa of Smerin- 
thus Populi. (Ibid.) 
19. Spiracle of the imago of Oryctes nasicornis. a. The boss. 
(Ibid.) 
20. Dorsal spiracle of Cermaiia. 
21. Pencil of hairs attached to a supposed respiratory plate 
in certain Noctuidce. Vol. IV. p. 60. 
22. Part of the back of the abdomen of the pupa of a Penta- 
toma. a. Pseudo- spiracle, b. Connecting corrugations. 
Vol. III. p. 713. 
23. Unilabiate spiracle of Gonyleptes. 
24. Portion of ventral segments of abdomen of Aradus lami- 
natus K. a. Tobaccopipe-shaped organ near the ven- 
tral spiracles. Vol. III. p. 713. 
25. Part of the back of the alitrunk of Belostoma grandis, to 
show the metapnystega ? or rather spiracle. Vol. III. 
p. 572; IV. p. 45. 
26. Pseudo-spiracle of Carkinodes cancriformis. Vol. III. 
p. 714. 
27. Part of the ventral segments of the abdomen of Lygceus 
compressipes. a. Pseudo-spiracles. 
28. Portion of dorsal segments of Dytiscus marginalis, to 
show the large anal spiracles. Vol. IV. p. 42. 
