536 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.52. 



them back among the bushes in copulation. In ovipositing the female 

 poises just over the water and as the wave passes beneath her drops 

 the tip of the abdomen into the water, raising it again as soon as 

 the wave has passed. Emergence occurred between 10 in the morn- 

 ing and 4 in the afternoon. Usually the n3^mph crawled just above 

 the wash of the waves. Eobins caught many of the tenerals among 

 the rocks. 



OPHIOGOMPHUS MORRISONI NEVADENSIS. new variety. 



Type.—Csxt. No. 21143, U.S.N.M. A male, Pyramid Lake, Ne- 

 vada, August 4, 1914. 



Allotype.— C&t. No. 21143, U.S.N.M. A female, Humboldt River, 

 Carlin, Nevada, August 7, 1914. 



Live colors, male. — Thorax greenish gray, abdomen pale yellow and 

 white, markings dark brown. 



Face pale greenish gray with an obscure dark line above labrum; 

 posterior edge of the horizontal surface of the frons black; vertex 

 black except oval postocellar pale spot; occiput yellow; eyes gray, 

 darker above (See fig. 178.) 



Thorax grayish oHve green with the following dark markings: 

 Middorsal stripe 1.5 mm, wide at lower end, narrower above. Ante- 

 alar ridge brown. Humeral stripe usually double, each member being 

 0.5 mm. wide at the upper or wider end. The stripes are widely sepa- 

 rated for their entire length. In two of the six males the anterior 

 humeral stripe is represented above by an oval spot only, and a small 

 dot below. (This form has been confused by Hagen with severus, 

 from which it differs in the pointed posterior hamules.) A black 

 line crosses the dorsal end of the mesinfraepistemum and connects 

 along the posterior edge of the same plate with a black line on the 

 lower third of the first lateral suture. Second lateral suture narrowly 

 black. Metinfraepisternum entirely yellow. Lateral alar ridge nar- 

 rowly brown. Femora creamy with dorsal surface of front femora 

 black, the distal half of the dorsal surface of the middle pair black 

 and the distal third of the hind pair black; tibiae black with an exter- 

 nal pale stripe; tarsi black. Wings lightly flavescent (not brownish 

 as in morrisoni). Costa pale yellow; veins brown; pterostigmas 

 grayish brown. 



Abdomen creamy yellow above, tinged with green on sides of seg- 

 ments 1 and 2, white on lower sides of segments 3-6, and chrome 

 yeUow on sides and dorsum of' segments 7-10. Sides with a saw- 

 toothed stripe, lacking on the anterior half of segment 3 and broken 

 on the anterior ends of segments 4-7. The dorsal angles of the 

 "sawteeth" of the lateral stripes meet broadly on the middorsal 

 line of the posterior end of segments 3-6. Segment 10 wholly 

 yellow, except a small spot on either side and a smaller one between 

 bases of dorsal appendages. Appendages yellow. Apical ventral 

 angle of segments 3-7 with a small black spot. (Hamulos, fig. 179.) 



