Empididae. 243 



terminates with a pair of hooks, and inwards there is a pair of small 

 lamellæ; in the interior lies also a long, curved, thread-like penis; 

 for the rest the apparatus is not quite symmetricai. In the female 

 the abdomen is somewhat thick towards the apex, and the ovipositor 

 is somewhat cm'ious; only six not transforrned abdominal segments 

 can be counted; the seventh dorsal segment is large, somewhat roof- 

 shaped, and excised at the apex, the seventh ventral segment is like- 

 wise large, triangularly pointed backwards; hidden in the interior lies 

 a small eighth segment, terminating with small styles. The legs are 

 long and slender; the front coxæ are only slightly elongated, half as 

 long as the femora, these latter are very slightly thickened; the front 

 femora have bristles below, and the posterior tibiæ have long bristles; 

 there are somewhat small apical spurs on the posterior tibiæ. There are 

 two elaws, two small pulvilli and a small, linear, bristle-bearing em- 

 podium. The wings with the mediastinal vein not reaching the margin; 



..„.„^,^,-.,^jY'-^^^"--— r_ 



Fig. 107. Wing of T. longicornis. 



the cubital vein forked, thus two cubital cells; the upper branch of 

 the vein long, parallel with the main branch; the discai vein forked, 

 thus four posterior cells; the discai cell long, sending three veins to 

 the margin, the third is the upper branch of the postical vein, which 

 closes the discai cell below; the lower branch of the postical vein 

 recurrent, almost parallel with the margin; the second basal cell 

 shorter than the first, the anal cell slightly shorter than the second 

 basal cell; anal vein very weak, not reaching the margin. Stigma 

 present, very faint. Axillary lobe small. Alula not present, the margin 

 here fringed. Alar squamula narrow, without fringe at the margin. 



The developmental stages of the genus are not known. 



The species of this genus is easily known by its long antennæ; 

 it is recorded to occur on meadows near water. 



The genus comprises only one species, also occurrlng in Denmark. 



1. T. longicornis Meig. 



1822. Meig. Syst. Beschr. III, 12, 1, Tab. XX, Fig. 6— 7 {Brachystoma). 

 — 1842. Zett. Dipt. Scand. I, 363,5, et 1859. XIII, 5004, 5 {Brachystoma). 



16* 



