| | PAGE |
| Fig. 1. Bombus, larva and nymph: after Packard | [11] |
| ,, 2. Ammophila | [22] |
| ,, 3-4. Spines on the tarsi of female Ammophila | [23] |
| ,, 5. Tubular entrance to hole of wasp | [25] |
| ,, 6. Basal segments of ants | [33] |
| ,, 7. Rose-leaf partially eaten by bees | [52] |
| ,, 8. Tufted hairs of hind leg of Andrena | [67] |
| ,, 9. Corbicula of humble bee | [67] |
| ,, 10-12. Cleaning apparatus of bees | [69] |
| ,, 13-18. Hairs of bees, magnified | [71] |
| ,, 19. Tongues of bees, magnified | [73] |
| ,, 20. Diagram of tongue of bee | [75] |
| ,, 21. Stylops | [77] |
| ,, 22. Stylops larva in abdominal cavity of bee | [78] |
| ,, 23. Antennæ of "Keyhole" wasps | [101] |
| ,, 24. Legs of male "Keyhole" wasps | [101] |
| ,, 25. Tibia of male Crabro cribrarius | [103] |
| ,, 26. Antennæ of male Crabro cribrarius | [103] |
| ,, 27. Head of male and female Crabro clypeatus | [103] |
| ,, 28. Parts of the insect | [133] |