10 ILLUSTRATIONS. 
, Haee. 
Fig. 27. Map showing distribution of Brood XXIV, 1912 73 
28. Map showing distribution of Brood XXVI, 1914 75 
29. Map sliow'ng distribution of Brood XXIX, 1917 70 
:'.0. Map sh(*wing distribution of Brood XXX, 1918 77 
;U. Head and prothorax of Cicada, lateral view 7N 
82. Head of ("icada, front view, right mandible and maxilla drawn out.. 79 
8;i. Head and prothorax of Cicada, lateral view, with parts separated lo 
show structure 80 
34. The periodical Cicada, side view, showing beak and ovipositor 81 
35. Abdomen of female, showing ovipositor and attachments 81 
36. Tip of ovipositor, much enlarged 81 
37. Cross section of ovipositor 82 
38. The musical apparatus of the periodical Cicada 83 
39. Pupal galleries of the Cicada 92 
40. Exit holes in soil 100 
41. Twigs showing egg punctures and illustrating manner of breaking .. . 100 
42. Twig showing scars from punctures after the second year 106 
43. Cicada scars in hard-maple twigs after seventeen years 108 
44. The egg nest of the Cicada, showing nature of wound and arrangement 
of eggs 109 
45. Egg, much enlarged, showing young about to be disclosed Ill 
46. Newly hatched larva, greatly enlarged 112 
47. First larval stage, illustrating the larva at the beginning and end of 
this stage 118 
48. Second larval stage, illustrating the structure of the anterior leg 119 
49. Third larval stage, illustrating the structure of the anterior leg 120 
50. Fourth larval stage, illustrating larva and structure of anterior leg 120 
51. First pupal stage, illustrating the structure of the anterior leg 121 
52. Cecidomyiid egg parasite of the Cicada 129 
53. Egg parasite, Lathromeris cicadf- 130 
54. Female Sphecius (digger wasp) carrying a Cicada to her burrow 130 
55. Diagram of the burrows of the digger wasp 131 
56. Cicada tibicen with wasp egg attached to thorax 131 
57. Full-grown larva of the digger wasp in its burrow feeding on a Cicada. . . 132 
58. Larva of digger wasp with anatomical details: pupa of same, front and 
lateral views 132 
59. Digger wasp larva constructing its cocoon 133 
60. Cocoon of digger wasp, with enlarged section of breathing pore 134 
61. Mite egg parasite, Oribatella sp 134 
62. Mite egg parasite, Oripoda elongata 134 
63. Mite egg parasite, Oppia pilosa 135 
64. Mite egg parasite, Pediculoides rentricosKS 136 
65. Mite egg parasit':^, Tyroglyphus cocciphilus 136 
66. Mite egg parasite, Iphis ovaiis 137 
67. Mite egg parasite, Cheylelus sp 137 
()8. ^lite egg parasite, Bdella sp ■ 138 
