ORTALIDJE — R1VELLIA. 91 



quite as far as the fifth longitudinal vein ; the hyaline interval 

 between them is broader and the intervening portion of the 

 costal cell of a darker coloring than in It. viridulans ; the costa 

 itself, from the extreme basis as far as about the middle of the 

 costal cell, is of a dirty-yellowish coloring. 



llab. Nebraska (?). [I possess a specimen from Washington, 

 D. C, which agrees exactly with the above description. O. S.] 



4. R. variabilis n. sp. % . — (Tab. VIII. f. 6.) Rufo-testacea, capite 

 pectoreque piceis, abdornine nigro-piceo, basiui versus pleruiuque di- 

 lutius piceo, pedibus luteis, tibiis posticis tarsorumque apice fuscis. 



Brick-red ; head and cbest pitch-brown ; abdomen pitch-black, towards 

 the basis usually of a lighter pitch-brown ; feet dark yellow ; bind 

 tibiae and the tip of all the tarsi brown. Long. corp. 0.18 — 0.21 ; long, 

 al. 0.15—0.2. 



Brick-red. Head pitch-brown or reddish-brown. Front of an 

 opaque dark-red coloring, on each side near the orbit with a 

 very narrow border of white pollen. Antennas reaching down 

 to the mouth ; the first two joints dark reddish-yellow ; the third, 

 with the exception of the basis, dark-brown, blackish towards the 

 tip. Palpi dark-brown. The chest and the lower part of the 

 pleurae dark pitch-brown. Abdomen pitch-black, generally lighter 

 pitch-brown near the basis. Coxae and feet dark-yellow ; the 

 four anterior tibiae but little infuscated ; the hind tibiae and the 

 last three or four tarsal joints dark-brown. Halteres dark-brown. 

 The picture of the w T ings almost entirely like that of It. quadj^i- 

 fasciata in coloring and design, only the first two crossbands 

 are a trifle longer and the first a little broader ; the brown col- 

 oring in the anterior basal cell is a little less extended. 



llab. District Columbia (Osten-lSaeken). 



Observation. — 1 have a female, from the same locality, which I 

 think belongs to the present species. It differs from the male, 

 described above, in having the antennas of an altogether dark- 

 yellow coloring, except the slightly infuscated tip of their third 

 joint ; the color in the middle of the thoracic dorsum almost 

 verges on blackish; the first crossband on the wings is a little 

 longer, the front and middle tibiae do not show any distinct infus- 

 cation and the tip of the tarsi is but little infuscated. 



