ILI.ISTKATIOXS 
PLATKS. 
Til"' transl'orr.uuion of [\\v periodical Ciciula ( 'rihicoi scplrndrri))!) I'^ront ispicro. 
I'l.A ri: I . Work of tlic ])(M"io(lical Cicada 12 
II. Fhotoiirajih of chambers of the periodical Cicada, geiieral \iew. 
taken at New Baltimore, N. Y., May, 1894 02 
III. Photograph of chambers of the periodical Cicada in woodshed. 
Washington, D. C, 1902 <M 
IV. Chambers of the periodical Cicada, natural size, in woodslicd, 
Washington, D. C, 1902 9(i 
V. Empty pupal shells of the periodical Cicada clinging lo leaves, 
Brood X. 1902, Washington, D. C 98 
VI. The Iransformalion of the emerged periodical Cicada 100 
TEXT FIGURES. 
Fir,. ]. The periodical Cicada, representing the typical form and dwarf form. . 21 
2. Map showing distribution of the broods of the 13-year race .3G 
3. Map showing distribution of the broods of the 17-year i-ace 37 
1. Map showing distribution of Brood I, 1910 39 
5. ^^ap showing distribution of Brood II, 1911 40 
0. Map showing distribution of Brood III, 1912 41 
7. Map showing distribution of Brood IV, 1913 42 
8. Map showing distribution of Brood V, 1914 44 
9. Map showing distribut ion of Brood VI, 1915 45 
10. :Map showing distribution of Brood VII, 1910 47 
11 . Map showing distribution of Brood VIII, 1917 18 
12. >rap showing distribution of Brood IX, 1918 -19 
13. Map showing distribution of Brood X, 1919 51 
14. Map showing distribution of Brood XI, 1920 54 
15. Map showing distribution of Brood XII, 1921 5(1 
10. Map showing distribution of Brood XIII, 1922 57 
17. Map showing distril)uticm of Brood XIV, 1923 59 
18. Map shf)wing distribution of Brood XV, 1907 01 
19. Map showing distribution of Brood XVI, 1908 02 
20. Map shoAving distribution of Brood XVII, 1909 03 
21. Map showing distrilnition of Brood XVIII, 1919 05 
22. Map showing distribution of Brood XIX, 1907 00 
23. Map showing distribution of Brood XX, 1908 OS 
24. Map showing distribution of Brood XXI, 1909 09 
25. Map showing distribution of Brood XXII, 1910 70 
20. Map showing distribul ion r.fBror.d XXIII. 1911 71 
9 
