THE CANADIAN ENTOMOLOGIST. 183 



Stigma, black. Length, 9 mm. Habitat — Juliaetta and Craig's 

 Mt., Idaho (Prof. J- M. Aldrich) atracostus, n. sp. 



20. Posterior femora in part black : 



Black, with the following parts yellow : the clypeus, the labrum, 

 the mandibles except at apex, a small spot on the cheeks, a line 

 on the collar, the tegulse, a spot above the posterior coxae, the 

 front legs beneath, the knees of the middle and posterior legs 

 beneath, and the middle and posterior tibi?e beneath ; the 

 following parts rufous : the front femora behind and at middle, 

 the middle femora beneath and at middle above, and the 

 posterior femora except a linear spot on the base and apex 

 above ; the third segment of the antennse one-fourth longer than 

 the fourth ; the clypeus broadly emarginate ; the wings hyaline ; 

 the veins, including the costa and the stigma, black. Length, 



8 mm. Habitat— Juliaetta, Idaho (Prof J. M. Aldrich) 



Aldrichii, n. sp. 



Posterior femora rufous 21. 



21. TeguliB and collar black 22. 



Tegulte and collar pale 23. 



22. Yellow spot above the posterior coxje nigrisofniniis, Harrg. 



Yellow spot above the posterior coxse wanting . . eryihroviertis, Prov. 



23. All the tibiae rufous ritjicoiiis, Harrg. 



Anterior tibiK black above 24. 



24. Posterior tibiae wholly rufous : 



Black, with the following parts yellowish-white : the clypeus, 

 the labrum, the mandibles except at apex, a small spot on the 

 cheeks, a spot on the upper posterior angles of the prothorax, 

 the tegulai, a spot on the ventral margin of the pronotum, 



. a spot above the posterior coxaj, a spot on the sides of the basal 

 plates, a fine line on the posterior margin of the basal plates, a 

 spot on the anterior coxae beneath, a small spot on the posterior 

 coxae above near the apex, and the front and middle legs 

 beneath (in some specimens the middle femora are wholly 

 rufous and in some the coxte are pale at apex) ; the legs beyond 

 the trochanters rufous except a black line above on the anterior 

 and middle tibiae (in one specimen the black line on the middle 



