236 



R. E. SNODGRASS. 



ig. 150 



' 151 



" 152. 



" 153. 



•' 154. 



" 155. 



" 156. 



" 157. 



" 158 



" 159 



•' 160. 



" 161. 



PLATE XVIII. 



Tipula trivitta, central vesicle (c. v.) and penis (p.), left side. 

 '' guard of penis, left side. 



" ventral view of bent bar lying between posterior arms 

 of central vesicle. 

 Tipula trivitta, apical appendages of left side, outer view. 

 " cognata, left view of bypopygium ; m, intersegmental membrane 

 between eighth segment and bypopygium. 

 Tipula cognata, ventral view of bypopygium with appendages removed. 

 spectabilis, tergum of bypopygium, dorsal view. 

 cognata, apical appendages of left side, outer view. 

 spectabilis, guard of penis, left side. 



" apical appendage of left side, outer view. 

 " distal half of abdomen, lateral view, x 10. 

 " ventral view of bypopygium. 



