LIST OF ILLUSTRATIONS. XI 



Page. 



Fig. 59. — Celaenura denticollis, pairs of eggs in tissue of grass leaf. 

 60-61. — Celaenura denticollis. 60. Pair resting between ovipositions, 

 female with abdomen raised. 6L Female ovipositing 501 



Fig. 62, A and B. — Celaenura gemina, female prothorax. 63-69. — Celae- 

 nura denticollis. 63, A and B. Female prothorax. 64-69. Nymph. 

 66. Mentum. 67. Mental lobe. 68. Segment 9 of female. 69. Caudal 

 gill 504 



Figs. 70-81. — Ischnura penes. 70. /. perparva. 71. /. demorsa. 72. /. ver- 

 ticalis. 73. I. damula. 74. /. erratica. 75. /. ramhurii credula. 76. 

 /. kelUcotti. 77. /. barberi. 78. /. clegans. 79. /. cervula. 80. /. posita. 

 81. I.pumilio (genotype). 82. — Ceraiura capriola, penis. 83-84. — Ne- 

 halennia irene, penis. 85-91. — Celaenura denticollis. 85. Penis. 86-87. 

 Wings. 88. Female, mesostigmal laminae. 89-91. Male, segment 10. 

 92-96. — Celaenura gemina. 92. Penis, 93. Female, mesostigmal lami- 

 nae. 94-96. Male, segment 10 506 



Figs. 97-105. — Taiiypteryx hageni. 97-98. Color pattern. 99. Labium. 

 100. Metathoracic tubercle. 101-103. Male, appendages. 104. Female, 

 segments 9 and 10. 105. Penis. 106-114. — Tanypteryx pryeri. 106- 

 107. Color pattern. 108. Metathoracic tubercle. 109. Penis. 110. 

 Hamules. 111. Segments 9 and 10 of female. 112-114. Male, append- 

 ages 509 



Figs. 11^12^.— Tachopteryx thoreyi. 115-116. Color pattern. 117-119. 

 Male, appendages. 120. Segments 9 and 10 of female. 121-123. Nymph. 

 122. Antenna. 123. Mentum. 124-125. — Tanypteryx pryeri, wings 512 



Figs. 126-129. — Tanypteryx hageni, wings. 130-132. — Tachopteryx tho- 

 reyi, wings 514 



Figs. 133-137. — Cordulegaster diadema. 133-134. Color pattern. 135. 

 Segment 10 of male. 136. Fore leg of male. 137. Segments 9 and 10 of 

 female. 138-143. — Cordulegaster dorsalis. 138-139. Color pattern. 

 140. Penis and hamules. 141. Segment 10 of male. 142. Segments 9 and 

 10 of female. 143. Eggs 518 



Fig. 144. — Vulvar lamina and ovipositors (from Ris) in: A. Sympetrum 

 frequens. B. Sympetrum matutinum,. C. Sympetrum eroticum, ven- 

 tral view. D. Same, lateral view. E. Sympetrum cordulegaster. F. 

 Uracis ovipositrix 519 



Figs. 145-146. — Cordulegaster dorsalis. 145. A. Nymph with protective 



coat of algae. 145. B. Exuvia. 146. Female ovipositing in stream bed_ 520 



Fig. 147. — Divided median tooth of middle lobe of nymphal labium (from 

 Needham). A. Cordulegaster dorsalis. B. Cordulegaster diadema 523 



Figs. 148-154. — Progomphus borealis.' 148. Color pattern. 149. Segments 

 9 and 10 of female. 150-151. Segment 2 of male. 152-154. Segment 10 

 of male 524 



Figs. 155-163. — Progomphus borealis, nymph. 157. First leg. 158. Men- 

 tum, detail. 159. Head. 160. Mentum. 161. Segments 9 and 10 of 

 male. 162-163. Segments 9 and 10 of female 528 



Figs. 164-169. — Ophiogomphus bison. 164. Color pattern. 165. Hamules. 

 166-167. Male, appendages. 168. Vulva. 169. Occiput of female. 170- 

 177. — Ophiogomphus morrisoni. 178-185. — Ophiogomphus morrisoni 

 nevadensis 532 



Figs. 186-191. — Ophiogomphus scverus montanus. 186. Color pattern. 

 187. Hamules. 188-189. Male, appendages. 190. Vulva. 191. Female, 

 occiput. 192-197. — Ophiogomphus severus. 198-203. — Ophiogomphus 

 arizonicus . 537 



