68 DIPTERA OF NORTH AMERICA. 



stigma, having, however, between the transverse humeral vein and 

 the tip of the auxiliary vein a rather large and almost hyaline 

 space ; it includes between the third aud fourth longitudinal veins 

 an oval transparent spot near the base of the discal cell ; it covers 

 the whole of the two posterior basal cells and fills up the two first 

 thirds of the discal cell, running then in a darker color behind 

 the fifth longitudinal vein as far as the tip of this vein, from whence 

 forming a band, it rises above the posterior transverse vein and is 

 connected with the remaining picture iu the neighborhood of the 

 small transverse vein. From the latter place a band runs obliquely 

 to the costal border, where it seams the tip of the wing and pro- 

 ceeds as far as the tip of the fourth longitudinal vein ; on the 

 third longitudinal vein it emits a parallel branch running to the 

 posterior border. The last portion of the third longitudinal vein 

 is only slightly curved ; the posterior transverse vein is slightly 

 oblique ; the small transverse vein is perpendicular and more than 

 one and a half of its length from the posterior transverse vein. 



Hab. United States. (Osten-Sacken.) 



Observation 1. — Tryp. fr atria resembles exceedingly the yellow 

 variety of Tryp. Heraclei Linn., and agrees with it especially in the 

 picture of the wings ; but it differs from it by its shorter and pro- 

 portionately broader wings, by the greater distance between the 

 two transverse veins, and the curve of the last portion of the third 

 longitudinal vein, which is less considerable. I found also the 

 borer of the palest females of Tryp. Heraclei always black, whereas 

 its color in Tryp. fratria agrees with that of the abdomen. 



Observation 2. — I have been of the opinion for some time that 

 this species might be Tryp. varipennis Macq., but after a closer 

 examination I find this not admissible, since in Macquart's figure 

 (Dipt. exot. II, 3, Tab. XXXI, f. 1) the baud rising from the 

 posterior border and seaming the posterior transverse vein includes 

 a large clear space behind the fifth longitudinal vein, which does 

 not exist in Tryp. fratria, and the penultimate band is united with 

 the first near the second longitudinal vein, whereas in Tryp. fratria 

 this union takes place at the third longitudinal vein. The state- 

 ment of the metauotum of Tryp. varipennis being black, whereas 

 in my specimen of Tryp. fratria it is marked with a black dot on 

 each side only, could not be considered as decisive for separating 

 the two species, since the species of this group are very variable 

 in their colors. 



