266 DTPTERA OF NORTH AMERICA. [PART IV. 



Ta}>le for determining the species. 



/■ Anterior margin of the wings shaded with brownish. 

 1 ^ 1 inconstans 0. S. 



i. Anterior margin of the wing not shaded with brownisli. 2 



o ( Wings spotted with brown. 3 



( Wings not spotted with brown, 4 



/-The inner end of the fourth posterior cell is in one line with the inner 

 „ ! end of the fifth and of the discal cells. 5 vernalis 0. S. 



j The inner end of the fourth posterior cell is beyond the inner end of 



^ the fifth and of the discal cells. 4 hyperborea 0. S. 



. ( First submarginal cell shorter than the second. 2 aiiripennis 0. S. 



i First submarginal cell longer than the second. 3 calcar 0. S. 



Description of the species. 



1. A. inconstans 0. S. % and J. — Ochracea, thorace rufescente, 

 abdomine obscuriori ; alarum margine antico et venulis transversis in- 

 fuscatis ; prsefurcae initium appendiculatum ; cellula submarginalis 

 prima secunda brevior. 



Ochraceous, thorax reddish, abdomen somewhat darker; anterior margin 

 of the wings and transverse veins infuscated ; the prsefurca has a stump 

 of a vein near its origin ; the first submarginal cell (in normal speci- 

 mens) is shorter than the second (Tab. II, fig. 15). Long. corp. 0.45 — 

 0.55. 



Syn. Amalopis inconstans 0. Sacken, Proc. Ac. Nat. Sc. Phil. 1859, p. 247. 



Coloring very inconstant ; ocliraceous, more or less mixed with 

 brown on the thorax and the abdomen ; sometimes altogether 

 without brown. The following is the description of the speci- 

 mens with a fullj developed dark coloring: — 



Kostrum and palpi brown ; front graj'ish ; under side of the 

 head yellowish ; antennte pale, but little longer than the head ; 

 basal joint generally brownish ; flagellum with moderate verticils. 

 Collare ochraceous, a black ring near the head, a brown stripe 

 along the middle ; mesonotum yellowish-orange, with a slight 

 brown tinge along the middle ; stripes Indistinct ; back of the 

 suture, the thorax is brownish ; scutellum and metathorax are 

 paler in the middle ; pleuroe pale ; haltercs pale ; feet yellow, 

 femora and tibite faintly brownish at the tip ; tips of the tarsal 

 joints, and their last joint brown. Abdomen brown, especially 

 towards the tip; male genitals brown; ovipositor reddish. Wings 

 tinged with light brownish ; anterior margin, especially within 



