Dolicliopodidae. 335 



a little notched in the lovver margin ^ Arista dorsal, placed on a 

 small peduncle ; in a single case (the American species virago Aldrich) 

 it is apical; it is somewhat short, or a little ionger than the antennæ; 

 the first joint is not long. The antennæ are of aboiit the same shape 

 and length in the two sexes, only when they are elongated, they are 

 longest in the male. The basal antennal joint is bare, the second has 

 bristles at the apex, the third is short-haired, and the arista very 

 short-haired, almost bare. Epistoma somewhat narrowed above, at 

 its lower end with a small tubercle on each side at the eye-margin, 

 separating it from the clypeus; this latter is a little arched with a 

 rounded lower margin, reaching about to the lower margin of the 

 eyes. Proboscis and oral aperture as in Hydrophorus, and of the 

 same size in both sexes. Thorax as in Hi/drophorus, but still longer, 

 with a small and indistinct declining part behind; postscutellum 

 somewhat large ; metaepimera broad, and metathorax distinctly seen 

 above. The acrostichal bristles uniserial, the dorsocentral bristles 

 numerous; further a humeral bristle, and a smaller one, a posthumeral, 

 only one notopleural, one supraalar and a postalar bristle; the præ- 

 sutural and anterior supraalar bristles still more reduced than in 

 Hi/drophorus, only represented by very small hairs. There are only 

 few and small hairs on the front part of the disc. Scutellum bare 

 above, with two marginal brisles. Propleura with hairs, and with 

 some prothoracic bristles below. Abdomen short; in the male there 

 are five dorsal segments of about the same length, the first the longest; 

 the fifth segment is narrowed, and behind it the small sixth is seen; 

 the seventh is small and hidden, and at the apex the eighth is seen. 

 The first ventral segment is small, the second, third and fourth about 

 normal, but the fourth arched downwards and somewhat forwards; 

 the rest are folded somewhat in for the reception of the hypopygium; 

 this latter is of medium size, not pedunculated, but somewhat visible 

 at the end of abdomen ; it is bent downwards and somewhat for- 

 wards, and the eighth segment is not lying much asymetrically ; there 

 are long posterior ventral lobes, as the sides of the cavity of the 

 hypopygium are prolonged into two processes, which are somewhat 

 narrow at the base and thus stalked, but broad in the apical part 

 and with a large, round exclsion at the end; they are only seen by 

 dissection ; the penis and its sheath are short. The outer lamellæ are 

 lancet-shaped, they are inserted inwards on the dorsal side, and they 

 are not quite free, but as in Medeterus somewhat united in the 



* Loew says about the antennæ (Mon. of Dipt. of N. Am. II. 1864, 200) in the 

 diagnosis of the genus that they are not excised on the edge; but in notatus 

 there is a small, but quite distinct excision (Fig. 104). 



