PLATE II. Structures of Head, Mouth, Thorax & Genitalia 1. Head of wasp from front. 2. Head of honey bee with mouth parts extended. 3. Head of Locustid from front, to show regions. 4. Head of a Lepidopteron from front. 5. Head of a cricket from front. 6. Labium of a cricket showing all usual parts. 7. Maxilla of Harpalus caliginosus, with all sclerites marked. 8. Mandible of Copris carolina with all sclerites defined. 9. Thorax of a Hymenopteron from above. 10. Genitalia of a male mosquito with all parts named. 11. Genitalia of a male Noctuid from below: the parts separated out. PLATE III. Venation According to the Comstock System. 1. Wing venation of a Noctuid. 2. Wing venation of a Hepialid. 3. Wing venation of a Locustid. 4. Wing venation of a Hymenopteron. 5. Wing venation of a Dipteron. 6. Wing venation of an Odonat. 7. Wing venation of a Cicada. Abbreviations are as follows: C. Costa, except in figure 1, where on the outer margin C occurs instead of Cu. In the cells it means Costal. Sc. Subcosta, when it refers to a vein and subcostal in a cell. R. Radius, when it refers to a vein and radial when in a cell. M. Media, when it refers to a vein and median in a cell. Cu. Cubitus, when it refers to a vein and cubital in a cell. A. Anal veins or cells. c-v. cross-vein. m-cu. medio-cubital cross-vein. r-m. radio-medial cross-vein. m. median cross-vein. h. humeral cross-vein. st. stigma. ar. arculus. br. bridge. n. nodus. o. oblique vein. t. triangle. i. internal triangle. al. anal loop. Antn-c-sp. Antenodal costal spaces. Ptn-c-sp. Postnodal costal spaces. Ptn-r-sp. Postnodal radial spaces. All cells are named after the vein that bounds them anteriorly and are numbered, if more than one, from base outwardly, as 2M3 = second median 3, etc. In figure 1, M, in the outer margin between C1 and M2, should be M3: the 3 was accidentally cut out by the engraver. Plate 1 Plate 2 Plate 3 COLOR PLATE. Nomenclature of Windsor and Newton's Water Colors. 1. Vermilion. 2. Carmine. 3. Crimson lake. 4. Alizar crimson. 5. Salmon. 6. Rose. 7. Purple madder. 8. Mauve. 9. French blue. 10. Purple lake. 11. Violet carmine. 12. Lilac. 13. Cobalt blue. 14. Lavender. 15. Blue gray. 16. Greenish gray. 17. Chrome lemon. 18. Gamboge. 19. Chrome orange. 20. Pale cadmium yellow. 21. Brown pink. 22. Pale clay yellow. 23. Hooker's green. 24. Prussian green. 25. Olive green. 26. Apple green. 27. Nile green. 28. Pale green. 20. Blue green. 30. Neutral. 31. Gray. 32. Ultra ash gray. 33. Indian red. 34. Dragon's blood. 35. Burnt sienna. 36. Brown ochre. 37. Cologne earth. 38. Roman sepia. 39. Van Dyke brown. 40. Pale brown.