132 DIPTERA OF NORTH AMERICA. [PART III. 



First longitudinal vein with bristles towards its end only ; the end of 

 the fourth longitudinal vein not curved forward : the posterior angle 

 of the anal cell drawn out in a narrow, exceedingly long lobe. 



Robust, black species, of the same general appearance as 

 Holodasia and Anacampta; the structure of the head more like 

 that of Pleropaectria ; the thorax generally shows longitudinal 

 lines of a paler-colored dust, answering to the intervals of the 

 ordinary thoracic stripes. The wings have complete crossbands. 



The typical species is the Or talis fasciata of Wiedemann, from 

 Chile, which is identical with the Tephritis quinquefasciata 

 Macq. Dipt. Exot. Suppl. IV, 291. 



The shape of the anal cell reminds very much of Diacrila; 

 nevertheless, there are no other points of relationship between 

 the two genera. 



Observation. — Should an American species be found which 

 does not Well flt in any of the above-described six genera, the 

 characters of the European genera should be compared; they 

 have been given in the part treating of the systematic distribu- 

 tion of the Ortalidse in general. 



Fifth Section: Pterocallina. 



Gen. I. PTEROCALLA Rond. 



Charact. — General appearance : Trypeta-like. 



Wings very narrow, in comparison to their length, of a rather striking 

 shape on account of their equal breadth, very broadly rounded at 

 the root and at the tip ; auxiliary vein much shorter than the first 

 longitudinal vein, so that the distance between the ends of both is 

 strikingly large ; first basal and discal cells very long ; posterior 

 crossvein very oblique, its anterior end being much nearer the apex 

 of the wing than its posterior end ; the posterior angle of the anal 

 cell drawn out in a moderately long lobe. 



The peculiarities in the outline of the wings and in the vena- 

 tion of the species belonging to this genus are so striking, that 

 no doubt can possibly arise about the location of any of them. 

 In some other respects, these species differ considerably from 

 each other, so that, should their number increase, it would be 

 necessary to break up the genus Pterocalla into smaller genera. 

 The name Pterocalla would, in this case, remain to the genus 

 which contains P. ocellata Fab., as Mr. Rondani established the 

 genus for this species. 



