| FIG. | |
| 1. | Gills of a spider. (Treviran.) |
| 2. | ———– Scorpio europÆus. (Ibid). |
| 3. | AËriducts of larva of Ephemera fusco grisea. (De Geer.) Vol. IV. p. 58. |
| 4. | —————————————– vespertina. (Ibid.) Ibid. |
| 5. | —————————————– vulgata. (Ibid.) Ibid. |
| 6. | ————————– Sialis lutaria. (Ibid.) Ibid. |
| 7. | Thread-like ditto of the upper and under side of the larvÆ of Trichoptera. (Ibid.) Ibid. p. 56. |
| 8. | Part of the body of the larva of a Libellula, laid open to show the tracheÆ. (Reaum.) a. a. a. TracheÆ. Vol. IV. p. 66. |
| 9. | Part of the imago of ditto. (Ibid.) a. Vesicles that terminate the tracheÆ. b. Oblong ditto. Vol. IV. p. 68. |
| 10. | Pupa of Corethra culiciformis. (De Geer.) a. b. Vesicles connected with the tracheÆ. c. Tail. Vol. IV. p. 67. |
| 11. | Part of the head of Armadillo zonatus. a. Pseudo-spiracle. Vol. III. p. 493. |
| 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 probably produce their noise. Vol. II. p. 391; III. p. 339. |
| 14. | Underside of part of the alitrunk of LygÆus sexmaculatus 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. |
| 16. | Spiracle of larva of Oryctes nasicornis. (Sprengel.) |
| 17. | ———————— Dytiscus marginalis. (Ibid.) |
| 18. | Part of the trachea and bronchiÆ of the pupa of Smerinthus Populi. (Ibid.) |
| 19. | Spiracle of the imago of Oryctes nasicornis. a. The boss. (Ibid.) |
| 20. | Dorsal spiracle of Cermatia. |
| 21. | Pencil of hairs attached to a supposed respiratory plate in certain NoctuidÆ. Vol. IV. p. 60. |
| 22. | Part of the back of the abdomen of the pupa of a Pentatoma. a. Pseudo-spiracle. b. Connecting corrugations. Vol. III. p. 713. |
| 23. | Unilabiate spiracle of Gonyleptes. |
| 24. | Portion of ventral segments of abdomen of Aradus laminatus K. a. Tobaccopipe-shaped organ near the ventral 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 LygÆus compressipes. a. Pseudo-spiracles. |
| 28. | Portion of dorsal segments of Dytiscus marginalis, to show the large anal spiracles. Vol. IV. p. 42. |
| 29. | Plumiform gills in the mouth of the spiracles of the larva of Cossus ligniperda. (Sprengel.) |
