NO. 2192. DRA00NFLIE8, CALIFORNIA AND NEVADA— KENNEDY. 531 

 OPHIOGOMPHUS SEVERUS Hagen. 



Live colors, male. — Thorax green, abdomen yellow, markings dark 

 brown. 



Face yellow; eyes gray; vertex black; rear of head yellowish; 

 occiput yellow. (See fig. 192.) 



Thorax m tenerals and young specimens clear pale green which 

 turns yellowish olive in old specimens. It is marked as follows: 

 Middorsal carina narrowly brown, which color extends along the an- 

 tealar sinus to the humeral suture. This is narrowly brown and in 

 some specimens the brown extends ventrad on the suture posterior 

 to the mesinfraepistemum. A small oval spot on the upper end of 

 the mesepistenmm. (Tliis spot distinguishes the species except from 

 arizonicus and some individuals of nevadensis.) Legs creamy with an 

 external black stripe on the femur of the first pair (in some specimens 

 on the outer half only), and on the distal half of the femur of the 

 second and third pairs; tibiae black with an external yellow stripe; 

 tarsi black. Costa yellow; pterostigmas gray, even in old speci- 

 mens. 



Abdomen lemon yellow above the lateral markings, except on sides 

 of segments 1 and 2, which are greenish; below the lateral markings 

 the sides pure white. A sawtoothed brownish black lateral stripe 

 on segments 2-9. In most males this stripe is broken into a series of 

 detached triangular spots, one on the side of each segment. Segment 

 10 with obscure traces of this band. In old specimens the green of 

 the thorax becomes yellowish olive, and the abdominal yellow deepens 

 to a chrome especially on the sides of segments 7-10. In such old 

 specimens the dark antehumeral spots fade and frequently disappear 

 altogether. 



Female. — Colored similarly to the male but the dark on the legs more 

 restricted and the triangular spots on the abdomen lengthened and 

 widened on the proximal end of each segment so as to give the effect 

 of a continuous sawtoothed lateral band. 



Tlie female is readily distinguished from the females of other species, 

 except arizonicus, by the narrow humeral stripe and the small oval 

 antehumeral spot. (Some females of nevadensis may be colored thus, 

 though the specimens I have possess the double humeral stripe.) 

 Both sexes are distinguished from nevadensis by the lack of black on 

 the second lateral suture of the thorax. The males are distinguished 

 by the spatulate tips of the posterior hamules. (See figs. 193-197.) 



Abdomen, male, 34-36 mm.; female, 35-36; hind wing, male, 28-29 

 mm.; female, 31-32. 



The only place I have found this species, with the exception of Uma- 

 tilla, Oregon, where I collected two specimens, is on Satus Creek, Ya- 

 kima County, Washington, where it is abundant from June 1 5 to August 



