1882.1 17G 



Calyplra yellowish-white, rather small, but with unequal scales. Unllcres 

 yellow. 



Legs black, with few hairs or bristles ; posterior femora rather long, almost 

 bare along their anterior two-thirds, but furnished witli a loose tuft of a few long 

 hairs on both sides of their hinder extremities; posterior tibiic bare, with tlie ex- 

 ception of two or three sliortish bristles on their outer sides. 



? rather smaller tlian $ . Head : eyes nearly bare, separated by a wide black 

 space, occupying nearly a third of the width of the head. Thorax and Ahdumen 

 of a brownish-grey colour, without markings. Wings clear. Other characters 

 similar to those of the male. 



This small species is generally distributed, especially in the North of England ; 

 it bears a good deal of resemblance in size, shape and colour to Mydaea vespertina. 



T. KOSTR.\.TUS, Sp. 11. 

 Mas, nigrescens ; ore valde producto ; abdomine glmico-cinereo, linea dorsali 

 effaciis transversis nigris signato ; iihiis posticis incurvis, apicibusque calcare aciito 

 armatis ; halterUms nigris. Long. 3 tin. 



Head : eyes long-haired, and contiguous ; forehead prominent ; face white, 

 with black reflections ; antenna? black and short, the third joint rather longer than 

 the second ; arista sub-pubescent ; lower surface of head flat, with the anterior part 

 projecting forward below and beyond the antenna; in the form of a snout ; opening 

 of the mouth large ; proboscis thick and rather elongated ; palpi jBliform and black. 

 Thorax black, clothed with thin grey tomentum, and without distinct stripes ; 

 shoulders greyish-white ; scutellum black. 



Abdomen hairy, conical, and rather elongated ; the four segments nearly equal 

 in length, the first black, the other three of a glaucous or greyish-white colour, with 

 black reflections, which show differently in different aspects ; when viewed from 

 before or the side, they assume the form of six semi-lunar spots, one placed on each 

 side of the base of each segment ; but when seen from behind, there appears to be 

 an interrupted central dorsal stripe, dilated at the posterior edge of each segment 

 into a triangular spot, the lower angles of the base of which are continued into a 

 transverse, widish black band, which encircles the posterior mai-gin of each of the 

 three last segments ; anal segment thickened, but without projecting appendages. 

 Calgptra well developed, white. Halteres black. 



Wings clear, third and fourth longitudinal veins divergent ; internal and ex- 

 ternal transverse veins near together, the latter straight. 



Legs black, with posterior femora ciliated along their whole under-surfaccs with 

 hairs of moderate and even lengths ; posterior tibia? curved inwards, shortly ciliated 

 along their outer sides, and armed with a strong sharp pointed spur a little before 

 their apex on their inner sides, which are otherwise nearly smooth. 

 The female is unknown to me. 



I have seen but one specimen of this well-marked and peculiar species, whicli 

 was in an imperfect condition, having lost the anterior tibiae and tarsi, and the middle 

 legs entirely ; it was in a collection of unnamed British Diptera made by the late 

 Mr. Francis Walker, the locality being unmarked. It is closely related to the A. 

 sitbrostrata of Zetterstedt, but differs essentially by having the posterior tibiije 



spurred. 



fTu be continued). 



