Merodon. 



479 



knees ; the anterior femora somewhat thickened, the hind femora con- 

 siderably thickened with a triangular tooth below near apex on the 

 anterior side; hind tibiæ broad in the apical two thirds, somewhat 

 thickened after the middle, with 

 a dilatation on the ventral side, 

 compressed before apex and here 

 especially incurved on the post- 

 erior side and the apex bent 

 somewhat towards this side; on 

 the posterior side the apex itself 

 is prolonged into a strong, flat- 

 tened and curved spur; all tarsi 

 somewhat broad. The legs haired 

 in the usiial way, the hairs on 

 femora rather long and dense ; 

 they are all or nearly all black, 

 and likewise on tibiæ or more 

 or less to quite pale on the 

 anterior tibiæ; there are some 

 longer hairs on the posterior 

 side of middle tibiæ and on the 

 dilatation below the hind tibiæ. 

 Wings almost hyaline or some- 

 what tinged. Stigma consisting only of the cross-vein. 

 and fringes smoky to black. Halteres brownish or black. 



Female. Vertex and frons somewhat broad, widening evenly down 

 to the antennæ; vertex and a middle stripe down to the antennæ 

 black, the sides of the frons brownish pruinose; the hairs black on 

 vertex, paler downwards but varying. The hairs on thorax all black, 

 on abdomen black on the basal half, yellow or reddish on the apical 

 half, or they are all yellow on thorax and yellowish grey on abdomen. 

 Hind femora less thickened than in the male, but with the same 

 triangular tooth; hind tibiæ almost simple and with no apical spur. 



Length 11 — 13, 5 mm. 



The above description is made from our few Danish specimens; 

 the males belong to the var. equestris (one specimen with the base of 

 abdomen black-haired answers to bulborum Rond.), while the females 

 are of the var. validus, except one specimen of the var. narcissi. In 

 other regions the species varies very considerably, from nearly all 

 black-haired to all pale-haired and with all intermediates ; the varieties 

 were not recognized as such and were consequently described as 

 species; now it is clearly recognized that we have only one species 



Fig. 161. Hind leg of M. equestris (J, 

 from the anterior side. X 12. 



Squamulæ 



