336 Orthorrhapha brachycera. 



middle; they are haiiy. On the dorsal side, behind the fourth seg- 

 ment, at the sides there issue two curious appendages, which I term 

 the subanal appendages; they are somewhat variously shaped in the 

 various species, generally more or less band-shaped, and of pale 

 colour; they are generally termed outer lamellæ, but this is erroneous, 

 as they have nothing to do with the hypopygium, but in reality issue 

 from the fifth ventral segment with a long peduncle, and are 

 directed upwards along the hind margin of the fourth dorsal segment ; 

 whether they have anything to do with the copulation I do not know ^ 

 In the female there are five normal abdominal segments, and the 

 abdomen terminates with an ovipositor with hairs, and with small 

 spines above. There are distinct dot-like impressions on the first to 

 fourth segments. Abdomen thinly clothed with short hairs, and 

 there are no hindmarginal bristles. Legs chiefly as in Hydrophorus; 

 the front legs raptorial, with the eoxæ somewhat elongated, femora 

 and tibiæ somewhat short, the femora thickened towards the base, 

 and both femora and tibiæ armed with long spines; these latter are 

 present in both sexes, but besides the males have on the tibiæ a 

 strong apical tooth and another on the ventral side; the apical tooth 

 is also present in the female, but small; the posterior legs are long 

 and slender, in the males they may be variously provided with hairs 

 and bristles; hind metatarsus longer than the second joint, without 

 bristles. The hind coxæ have a pair of small bristles on the outer 

 side; femora without preapical bristles; the posterior legs otherwise 

 with scattered bristles, and the posterior tibiæ with some apical or 

 preapical bristles. There are two claws, two well developed pulvilli, 

 and a somewhat large, narrow, lobe-shaped but not pulvilliform em- 

 podium, with bristles below. Wings long and narrow, generally more 

 or less marked with dark markings; the mediastinal vein elongated, 

 not terminating in the subcostal vein; the last part of the discai vein 

 with a larger or smaller curve and somewhat converging towards the 

 cubitai vein; posterior cross-vein behind the middle, the last part of 

 the postical vein not longer than the cross-vein ; anal vein short. The 

 axillary lobe somewhat well developed. The discai vein with a con- 

 vexity on the curve. Squamulæ as in Hydrophorus with a small 



Loew (Mon. of Dipt. of N. Am. II, 1864, ;201) vvas clear with regard to the faet 

 that these organs could not be the outer lamellæ; he had correctly seen that 

 they issue farther dovvnwards than is apparently the case, and he therefore 

 thinks that they might perhaps be the inner lamellæ; he says that inner 

 lamellæ would otherwise be wanting, as he had not, because of their hidden 

 position, seen the organs (posterior ventral lobes), which he terms inner 

 lamellæ. 



