134 STRATIOMYID^ 



This species is easily distinguished from any other European one by 

 the glancing silvery, or golden, felt-like clothing of the abdomen ; the 

 elongate basal joint of the antennae also distinguishes it from most species. 

 It may vary a little in the size of the abdominal spots, as a Bavarian male 

 in Kowarz's collection has them larger and more triangular so that they 

 become fairly conspicuous ; the orange red postocular collar may apparently 

 be limited to the lower half of the head or may extend right up to the 

 upper corner of the eye. 



0. arcjentata is either very uncommon in England now or it has been 

 remarkably overlooked, possibly because it is only a May species ; Walker 

 says "South of England; not common," and Brunetti says "Not 

 " uncommon. On willows. Generally distributed." I have never met 

 with it myself, and only know of one or two recent specimens, one of 

 which was taken by Colonel Yerbury at Fordingbridge in Hampshire on 

 May 6, 1897, and the other was I think taken by Dr D. Sharp at probably 

 Mildenhall in Suffolk about 1901. I have seen a specimen which was 

 taken by Mr Unwin at Seaford in Sussex prior to 1860, and the British 

 Museum possesses the species from Dorset through Mr Dale; Duncan 

 (1837) quotes "Cambridge, 1832. — Charles C. Babington, Esq." It does 

 not appear to be uncommon in old British collections, and one old specimen 

 in my collection bears a label " Kirby." It is recorded from North and 

 Middle Europe, and Lundbeck states that it was once found (May 6, 1843) 

 in Denmark in great numbers, the females sitting upon flowers of Salix 

 while the males sat on dead rushes looking like silver spots, and the males 

 were extremely quick and were seen hovering in the air in small swarms. 



Synonymy. — Of four males in the Hope Museum at Oxford two were labelled 

 "atrata." It may appear remarkable that I suggest Macquart's Exochostoma nitida 

 as a probable synonym of this species, but I am led to that opinion by the fact of 

 Bigot's Exochostoma caloceps (Ann. Soc. Ent. France, 1879, p. 217) from Colorado 

 being in my opinion a true Odontomyia in spite of its unarmed scutellum, and then 

 a re-examination of Macquart's description and figure brings his E. nitida, if 

 an Odontomyia, to the neighborhood of 0. arcjentata because of its elongated basal 

 antennal joint and its bare eyes ; if once reduced to this, the remarkable coloration 

 of the legs agrees very closely with 0. argentata, and the fact remains that in more 

 than sixty years no further record of the capture of so accessible a species exists ; I 

 am therefore of opinion that Macquart had before him only some specimens of the 

 female of 0. argentata in very bad condition, and that he drew very much ujion 

 his imagination in describing details and in drawing his figures. I only make the 

 suggestion that this may account for the non-reappearance of Exochostoma nitida, 

 as I have had no opportunity of examining the original specimens. 



2. O, tigrina Fabricius. All black, except the tibiae and tarsi. Eyes 

 of the male hairy. Cubital vein forked. 



The blackest of all the medium -sized Stratiomyidce. 



$ . Head broad and depressed when viewed from in front ; face and frons con- 

 siderably bulged out, shining black, and forming an equilateral triangle with 

 slightly arched sides ; face at its widest part little more than one-third the 

 width of the head; jowls broad but flat and consequently hardly visible 

 except from below ; mouth side-lips not so large as in 0. argentata; all the 

 frons and face clothed with long porrected dense black pubescence, but the 

 pubescence on the jowls and round the mouth is rather longer, more straggly 

 and hanging down, and includes numerous grey hairs and also black hairs 

 with grey tips ; lower half of the back of the head puffed out and black, with 



