TRYPETIDAE. 89 



dinal veins there is only a single clear drop on the anterior side of 

 the antepenultimate portion of the fourth longitudinal vein. The 

 want of that drop which is usually inside of the said interval be- 

 yond the small transverse vein, is very characteristic of this species, 

 as is also the considerable depth and blacker color of the convexity 

 existing there. In the discal cell there is always one drop on the 

 hind side of the penultimate portion of the fourth longitudinal 

 vein, and one or more such drops on the anterior side of the 

 fifth longitudinal vein. The third posterior cell and the axillary 

 angle of the wing have a reticulation produced by a few, propor- 

 tionately large, hyaline drops. The reticulation of the wings 

 emits ten rays to the borders, corresponding to those of Tryp. 

 festiva, except that the first ray of the latter species is wanting 

 totally in Tryp. bella, and the two rays described under No. 3 in 

 Tryp. festiva are reunited into one single ray in Tryp. bella ; the 

 last ray in Tryp. bella is usually connected again with the remain- 

 ing reticulation ; in this case the second posterior cell also con- 

 tains a separated clear drop. Posterior transverse vein not quite 

 perpendicular. 



Hab. Washington. (Osten-Sacken). New York. (Dr. Fitch.) 

 Observation. — Among the specimens forwarded by Baron Osten- 

 Sacken there was one bearing the name of Acinia bella Fitch. I 

 have therefore adopted this name for this fine new species. 

 Note. — Very common on Ambrosia artemisicefolia. — 0. S. 



22. T. latifrons Loew. $. (Tab. II, fig. 22.)— Obscura, capite, tibiis 

 tarsisque flavescentibus, fronte latissima, scutello convexo biseto, alis 

 latinscnlis, parce et satis sequaliter nigro-fusco reticulatis et in apice 

 breviter radiatis, bulla cellulse posterioris prima? permagna. 



Obscure ; bead, tibiae, and tarsi yellowisb ; front very broad ; scutellum 

 very convex, with two bristles ; wings ratber broad, witb tbe blackisb 

 reticulation ratber uniform, but little crowded, and emitting snort rays 

 at tbe tip ; tbe first posterior cell witb a very large convexity. Long, 

 corp. 0.30. Long. al. 0.27. 



The single specimen of this species which I have seen being oily, 

 I can say nothing certain about the color of its body. On the upper 

 side of the thorax there is a broad, simple intermediate stripe, and 

 on each side a bipartite lateral one, moreover a darker streak above 

 the base of the wing. Metanotum black, shining. The last abdo- 

 minal segment shining blackish-brown. Head yellowish ; front 



