ILLUSTRATIONS. 
PLATES. 
Pag< . 
The transformation of the Cicada Frontispiece 
Plate I. Work of the periodical Cicada 1<> 
II. Photograph of Cicada chambers, general view, taken at New Balti- 
more, X. Y.. May. 1894 • i* i 
III. Two photographs of Cicada chambers, more enlarged than Plate II. 
taken at New Baltimore, X. Y .. May. 1894 
FIGURES. 
FlG. 1. The periodical Cicada, representing typical form and dwarf form 18 
2. Map showing distribution of the broods of the 13-year race 23 
3. Map showing distribution of the broods of the 17-year race 26 
4. Map showing distribution of Broods XVII and VII, 1898 29 
5. Map showing distribution of Brood XIX, 1£99 :'>1 
6. Map showing distribution of Brood XX, 1900 32 
7. Map showing distribution of Broods XXI and X, 1901 33 
8. Map showing distribution of Brood XXII, 1902 3."> 
9. Map showing distribution of Brood I, 1903 36 
10. Map showing distribution of Brood V, 1905 37 
11. Map showing distribution of Broods XYI and VIII, 1906 39 
12. Map showing distribution of Brood XVIII, 1907 11 
13. Map showing distribution of Broods IX and II, 1908 12 
14. Map showing distribution of Brood IY. 1909 43 
15. Map showing distribution of Broods VI and XI, 1910 41 
lti. Map showing distribution of Brood XII, 1911 16 
17. Map showing distribution of Brood XIII, 1912 17 
18. Map showing distribution of Brood XIV, 1913 48 
19. Map showing distribution of Brood XV, 1914 19 
20. Head and prothorax of Cicada, lateral view ."1 
21. Head of Cicada, front view, with right mandible and maxilla drawn out . 52 
22. Head and prothorax of Cicada, lateral view, with parts separated to 
show structure 53 
23. The periodica] Cicada, side view, showing beak and ovipositor 54 
24. Abdomen of female, showing ovipositor and attachments 
25. Tip of ovipositor, much enlarged ."» \ 
26. Cross section of ovipositor 55 
27. The musical apparatus of the periodical Cicada 56 
28. Pupal galleries of the Cicada til 
29. Clay buildings of the periodical Cicada G6 
30. Twigs showing egg punctures and illustrating manner of breaking 7(5 
31. Twig showing Bears from punctures after the second year 76 
32. Cicada scars in hard-maple twigs after seventeen years 77 
33. The egg nest of the Cicada, showing nature ol' wound and arrange- 
ment of eggs 79 
