194 C. M. Osten Sacken: Diptera 



Head, including the antennae, reddish-yellow; in the middle of the 

 face a black or brown spot, emarginate below, narrower above, not 

 reachiug the foot of the antennae, nor the peristoma; frontal orbits 

 black, which color stops before the vertex (in a line with the ocelli) ; 

 antennal arista plumose. Thorax brown, with a microscopic, appressed 

 golden-yellow pubescence above; humeri and scutellum yellow; a 

 brownish-yellow, often indistinct, stripe begins at the corner of the 

 scutellum, passes above the root of the wing and stops at the thoracic 

 suture, where it is a little curved towards the inside ; a similar, brownish- 

 yellow, often indistinct, stripe along the dorso-pleural suture; pleurae 

 brown, with a longitudinal yellow stripe in the middle, which stops 

 between the root of the wing and the middle coxa. Legs brownish- 

 yellow, including the coxae; front tibiae and tips of all the other 

 tibiae brown; sometimes also more or less distinct brown marks in the 

 middle of the femora, Wings subhyaline, the apical third brownish, 

 in the middle of the wing this tinge nearly reaches the anterior cross- 

 vein; it is much less extended near the margins. Halteres reddish- 

 yellow. Abdomen brown, pubescent, sometimes the last segments yello- 

 wish on the margins. Venation like Chyliza vittata M.; only the 

 posterior crossvein less oblique and the anal cell a little shorter in 

 comparison to the second basal. — Three males, one female. — 



Micropezidae. 



The best characters for the Classification of this interesting family 

 may be derived from the structure of the male genital appendages and 

 the relative length and shape of the abdominal segments; but, unfor- 

 tunately the shrinkage and distortion of these Organs in dried speci- 

 mens renders their study very uncertain. Next to these, the chaeto- 

 taxy aflfords some good characters for the description of groups 

 and genera. 



The chaetotaxy of the Micropezidae, as far as I can make it out 

 from the small materials accessible to me, may be described as follows: 



All the genera that I have examined have one character in common, 

 the absence of the ocellar pair of bristles. Tanypeza which has 

 it, can hardly be considered a Micropezid. 



I. The two pairs of vertical bristles are present, although some- 

 times far apart, on account of the development of the back head. The 

 post-vertical pair is often, but not always, present. One fronto- 

 orbital bristle is inserted a little below the ocelli, (in Grammicomyia. 

 a little higher than the ocelli; I perceive none in Micropeza) ; and ge 

 nerally one, or even two (Calobata territa n. sp.) lower down; some- 

 times the latter bristles are very minute, (Nerius duplicatus.). 



