PELASTONEURUS. . 105 



Coxne and pleuraB black, with a silvery lustre. Scutellum with 

 velvet-black lateral spots and with a velvet-black middle-stripe, 

 smooth steel-blue between the corners and the middle stripe. Ab- 

 domen with a violet lustre. Hypopygium black, upon the under 

 side covered with snow-white dust, pedunculated, not very stout, 

 but very long, so that it reaches as far as the basis of the abdo- 

 men ; the comparatively small lamellae brownish-black ; the inte- 

 rior appendages slender, black, provided at the tip with not very 

 numerous but long hairs in the shape of a brush. Feet brownish- 

 yellow, hind femora blackened on the upper side of the extreme 

 tip ; the bristles on the upper side of the tibiae are inserted upon 

 irregular small black-brown spots ; tarsi dark brown, paler at the 

 basis. Cilia of the tegular black. Wings comparatively small 

 and narrow, tinged with blackish-gray and darker towards the 

 end of the anterior margin. 



Hab. New York. (Osten-Sacken.) 



Observation. — The punctation of the tibiae may remind one of 

 Dolicliopus maculipes Walk. This species is described as only 

 one and a half lines long and bronze-green, and with all the 

 femora having black tips. Xo mention whatever is made in Mr. 

 Walker's description of the very peculiar structure of the face 

 and of the striking white spots on the thorax, which are peculiar 

 to Pelastoneurus longicauda. Under such circumstances the 

 identification of these two species is impossible, the more so as all 

 the species of Pelastoneurus are very much alike and as the spots 

 on the tibiaa are a character which frequently occurs in this genus. 



2. P. lugubris Loew. J . — Niger, thorace fusco-pollinoso, opaco, ciliis 

 oculorum inferioribus nigris, alis nigricantibus. 



Black, thorax covered with brown dust, dull ; cilia of the inferior orbit 

 black ; wings blackish. Long. corp. 0.11. Long. al. 0.10. 



Syn. Pelastoneurus lugubris Loew, Neue Beitr. VIII, 38, 2. 



Black. Face black, with a whitish, not shining dust, and with 

 a blackish-brown, not well defined middle stripe; upon the larger, 

 inferior part but moderately convex. Palpi rather large, black, 

 on the outside with a thin whitish dust and black hairs. Front dull, 

 brownish-black. Antennae reddish-brown, the basis of the first 

 and the larger part of the third joint brownish-black ; the third 

 joint is small and rather rounded, beset with short but distinct 



