DTTRHAM DIPTERA. 235 



XXXI. 416. 



11 (10). Dorsum with only three central post-sutural bristles. 



12 (13). Male anus with both the anal segments shining black 



and exposed. (1862. melanura, Mg.) 



13(12). First segment of the male anus generally concealed, 

 and, when exposed, grey, not black. 



(1863. agrkola, Mg.) 



14 (3). Male hind tibiae not thickly haired on the inner side. 



15 (22). The second abdominal segment with two central hind 



marginal bristles. 

 10 (19). Arista short haired. 



17 (18). Arista almost bare; third antennal joint thickened. 



(1864. laticornis, Mg.) 



18 (17). Arista with short but distinct hairs at the base ; 



antennae normal. (1865. 7iigriventris, Mg.) 



19 (16). Arista long haired. 



20 (21). Abdomen tesselated. (1866. juvenis, Rnd.) 



21 (20). Abdomen with three black stripes. 



(1867. clathrata, Mg.) 



22 (15). The second abdominal segment without central hind 



marginal bristles. 



23 (24). Abdomen normally tesselated ; male hind tibiae with 



short soft hairs. (1868. adolescens, Rnd.) 



24 (23). Abdomen with central stripe and side spots ; male 



hind tibiae bare. (1869. affinis, Fin.) 



25 (2). V.l.b. with bristles. 



26 (27). Abdomen tesselated. 



(1877. hcetnorrhoa, Mg., var. setifiennis, Rnd.) 



27 (26). Abdomen spotted or striped. 



28 (29). Eyes of the male approximate. (1870. dissimilis, Mg.) 

 29(28). Eyes of the male wide apart. (187 1. infantula, Rnd.) 



30 (1). Apex of the abdomen red in both sexes. 



31 (32) V.l.b. and V.3. with bristles. (1877. hamorrhoa, Mg.) 



32 (31). V.l.b. bare, only V.3. with bristles. 



33 (34). Hind tibiae of the male bare on the inner side. 



(1876. hcematodes, Mg.) 



34 (33). Hind tibiae of the male long, and thickly haired on 



the inner side. 



