SAKCOPHAGA AND AI.LIES 197 



rounded at tip; posterior ciaspers long, rather 

 straight, blackish brown, shining, moderately curved 

 and pointed at tip; anterior clasper similar but 

 straighter and more depressed; penis mostly shining, 

 blackish, basal segment elongated, the distal segment 

 on the back with a narrow keel at the base, widening 

 at the middle into a prominence on each side, then 

 narrowing rapidly to a slender brownish process di- 

 vided near the tip and bent forward. From the 

 center of the distal segment arise two pairs of 

 slender, black, straight processes, which extend 

 straight out as far as the posterior organs go, and 

 then curve forward. On the anterior side of the base 

 of these arise two shining black elongated plates with 

 two notches in the apex, enclosing between them 

 some softer tissues. As the figure shows, those api- 

 cal developments of the distal segment are quite sep- 

 arated from eacli other, giving the organs a unique 

 appearance. Fifth sternite with a wide V-shaped 

 opening, fringed with only a few bristles. 



Legs black; middle femur without comb; mid- 

 dle tibia with three bristles on the outer side and some 

 erect villosity on the inner side; hind femora curved 

 but not much enlarged; hind tibia with erect villosity 

 spreading both ways. 



Wing subhyaline; no costal spine; third costal 

 segment longer than fifth and sixth together; first 

 vein bare ; third vein hairy more than half way to the 

 crossvein. 



Female. Front .327 of head. Outer vertical 

 bristles distinct; bucca about one-half of the eye- 

 height; scutellum without apical bristles; hind mar- 

 gin of fourth segment red on outer part ; genital seg- 

 ment yellow, rather protuberant, with vertical slit 

 bordered with long black bristles. A small costal 

 spine. 



Length 13 to 15 mm. 



Six males and one female; Moscow, Idaho, most- 

 ly collected Sept. 9, 1908, resting on stones at the 

 summit of Cedar Mountain near Moscow, Idaho. 



