532 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 52. 



15. The eggs are laid on the riffles. In ovipositing the females oper- 

 ate from stones in the rapids. A female will fly out from a seat on a 



Figs. 164-169.— OpmoGOMPHUS BISON. 164. Color pattern. 165. Hamules. 166-167. Male, appen- 

 dages. 168. Vulva. 169. Occiput of female. 

 Figs. 170-177.— Ophiogomphus morrisoni. 

 Figs. 178-185.— Ophiogomphus morrisoni nevadensis. 



stone, make one tap on the water with her abdomen, and then retm-n 

 to rest for a moment, when she repeats the single tap. The imagoes 

 emerge during tlie middle of the day from the deeper pools. 



