104 DIPTEEA. 



antero-proximal half of the wings : in A. pluto the dark spots on that portion of the 

 wings are larger and more or less coaleseent ; in A. seriepunctata, on the contrary, the 

 antero-proximal half of the wings is prevailingly hyaline. I strongly suspect that 

 A. seriepunctata is nothing but a variety of A. pluto ; nevertheless, I have not seen any 

 intermediate forms, and the four specimens of the former species which I have before 

 me are identical in colouring, although taken in two rather distant localities. Until 

 further evidence is forthcoming I prefer to treat A. seriepunctata as a distinct 

 species. 



8. Argyramceba daphne, sp. n., <? $ . (Tab. II. fig. 6.) 



Male. Head black, the face and front beset with black, erect hair, between which shorter, pale yellow, scaly 

 hairs are visible (especially on the front) ; frontal orbits hoary ; antenna? black, of the usual structure ; 

 occipital orbits with rare, pale-yellow, scaly hairs. Thorax greyish-black, with a black, erect pubescence 

 of delicate hairs and a rather rare and easily rubbed-off brownish -golden appressed tomentum, forming in 

 well-preserved specimens a pair of very indistinct stripes ; on the scutellum this same tomentum, mixed 

 with whitish scaly hairs, forms a border all around and a median line, bisecting the scutellum ; the upper 

 part of the pleurae, especially the interval between the humerus and the base of the wing, is beset with 

 long black hair, mixed with shorter white hairs ; the latter form an indistinct stripe passing from the 

 humerus, above the root of the wing, to the post-alar callosity. First segment of the abdomen with a tuft 

 of white hair on each side ; the following three segments have, besides the usual black, erect pile, a rather 

 rare covering of yellowish-brown, short, semiappressed hairs, visible especially on the second and the 

 anterior portion of the third segment ; on each side of the third segment a large spot of white scaly hairs ; 

 a fringe of similar whitish scales, interrupted in the middle, along the posterior margin of the same seg- 

 ment ; posterior half of the fourth segment, except in the middle, and all the following segments, covered 

 with white, almost silvery scales ; the black erect pile of the abdomen is especially visible on the third 

 segment and along the lateral margins, where it forms tufts, the largest of ^which is on the second 

 segment ; venter with rare appressed yellowish hairs and longer black ones. Forceps protruding, black ; a 

 pair of upper valves rufous, black at the tip ; lower valve sometimes also rufescent. Tegulae whitish ; knob 

 of the halteres brown, edged with whitish. Legs black, the tibiae and tarsi more brownish, with black 

 spines and scattered yellowish scales. Wings hyaline, brown at the base as far as the humeral cross-vein, 

 beyond which the interval between the costal and auxiliary vein is only greyish, while that between the 

 auxiliary and the first vein is darker brown ; a square brown spot in the middle of the first basal cell, 

 leaning on one side on the second vein, near its origin, on the other on the fourth vein, immediately before 

 its bifurcation ; this spot is connected with the brown at the base by a narrow stripe of the same colour 

 running along the first and second veins ; thus in the proximal half of the first basal cell only an elongated, 

 narrow hyaline space is left along the fourth vein ; second basal, anal, and axillary cells hyaline ; a brown, 

 spot on the small cross-vein, covering also the bifurcation of the second and third veins ; smaller, but 

 distinct dark brown clouds on the vein separating the second basal from the fourth posterior cell, and on 

 the bifurcation of the third vein ; the other clouds are pale, small, often altogether indistinct (at the 

 proximal end of the third and second posterior cells, the cloud on the latter especially, is, in most specimens, 

 altogether obsolete). Stumps of veins (rather long) on the knee of the second vein and on the fork of 

 the third ; none elsewhere. 

 Length 9-10 millim. ; smaller specimens occur, down to 5 millim. 



Female. Differs principally in the absence of the covering of white scales on the distal half of the abdomen ; 

 the yellowish-brown semiappressed hairs form indistinct cross-bands on the anterior portion of the inter- 

 mediate segments, expanding into broader patches in the middle of the segments ; large spots formed by 

 white scales on each side of the third and fourth segments ; a few white scales along the hind margins of 

 the same segments ; segments 6 and 7 likewise with some white scales on the sides. "Wings as in the 

 male, except that there is a brown cloud within the marginal cell, connecting the brown spot at the base 

 of the first submarginal and first posterior cells with the brown of the costa (in the male this interval is 



