ORTALIDiE — INTRODUCTION. 9 



of the wings, and all four agree among themselves in the ab- 

 sence of bristles on the first longitudinal vein, and this character 

 they share with some of the .genera placed among the Ortalidse. 



The genera Palloptera and Toxoneura possess moreover another 

 striking character, which occurs also among some few of the 

 genera of Ortalidse, but in none to that marked extent; they have, 

 upon the middle of the otherwise short-pilose, thoracic dorsum, as 

 far as its anterior part, a series of binary bristles, distinguished 

 by their length, stoutness, and regular arrangement. The dif- 

 ference in the venation already spoken of, together with this 

 marked peculiarity in the arrangement of the bristles of the 

 thorax, seem to afford sufficient ground for excluding those two 

 genera from the family Ortalidse. I consider them as the 

 nucleus of a separate family, which I call Pallopteridse. 



The systematic position of Lonchsea is more difficult to de- 

 cide upon than that of Palloptera and Toxoneura. "While the 

 venation of Lonchsea closely approaches these two genera, the 

 position of the bristles on its thorax is more like that of many Orta- 

 lidse, as there are no stronger bristles on the thoracic dorsum, 

 anterior to the suture ; this genus stands therefore nearer to the 

 undoubted Ortalidse than Palloptera or Toxoneura. Against 

 its being united with the Ortalidse may be urged (not to men- 

 tion the smallness of the two posterior basal cells), not so much 

 those characters which are common to all Lonchsese, as a number 

 of peculiarities, which do not occur among the Ortalidse, and 

 which distinguish different species of Lonchsea, and are quite 

 proper to form the basis of a subdivision of this widespread 

 and rather numerous genus. As such characters I consider the 

 long and strong hairs upon the whole body of some species, the 

 long and dense pubescence of the eyes of others, the partial 

 coalescence of the auxiliary vein with the first longitudinal in 

 several, and finally the circumstance that in the females of 

 some species the sixth abdominal segment does not take part 

 in the formation of the ovipositor quite in the same manner as 

 among the Ortalidse. I am afraid that the Ortalidse, as a 

 family, would lose too many of their well-defined characters, if, 

 in order to accommodate Lonchsea among them, we undertook 

 to modify these characters in accordance with the above men- 

 tioned peculiarities of the latter genus. The nature of the 



