WALKEB ON DIPTERA OF AKU ISLANDS. 81 



15. Sargus complens, n. s. Fcem. Rufescente-fulvus, capitis vertice 

 nigrO;, antennis testaceis, abdomine fasciis latis abbreviatis piceis, 

 tarsis posticis basi tibiisque posticis nigris, alis cinereis, basi sub- 

 luridis, apud costam exteriorem nigro-fuscis. 



Female, Reddish tawny. Head black above, testaceous beneath ; an- 

 tennae testaceous; abdomen with four broad abbreviated piceous 

 bands; legs tawny, hind tibiae black with a tawny apical mark, 

 hind tarsi black towards the base ; wings greyish, slightly lurid towards 

 the base, blackish-brown about the exterior part of the costa, veins 

 black, tawny towards the base ; halteres testaceous, tawny towards 

 the tips. Length of the body 6 lines ; of the wings 14 lines. 



16. Sargus rogans, n. s. Mas et Fcem. Capitis vertice nigro, an- 

 tennis pedibusque testaceis, tibiis tarsisque posticis nigris, alis sub- 

 cinereis apice obscurioribus. Mas. Luteo-testaceus. Fcem. Ferru- 

 gineus. 



Male and Female. Head black above ; antennae and legs testaceous ; 

 hind tibiae and hind tarsi black ; wings greyish, darker towards their 

 tips ; veins black, tawny towards the base. Male. Lutescent testa- 

 ceous. Female. Ferruginous ; wings darker than those of the male. 

 Length of the body 6 lines ; of the wings 10 lines. 



G-en. Nebua, n. g. 



Foem. Corpus longiusculum, sublineare. Caput transversum, thorace 

 non latins. Antennce breves ; aiticulus tertius rotundus ; arista api- 

 calis, longa, tenuis, setiformis. Thorax productus. Scutellum spinis 

 quatuor longiusculis. Abdomen depressum, sublineare, thorace vix 

 latins, non longius. Pedes graciles, non longi. Ake angustae ; venae 

 bene determinatae. 



Female. Body rather long, nearly linear. Head transverse, not broader 

 than the thorax. Antennae short ; third joint round ; arista apical, 

 long, slender, setiform. Thorax long. Abdomen flat, thin, nearly 

 linear, hardly broader and not longer than the thorax. Legs slender, 

 not long. Wings narrow ; veins distinctly marked, in structure like 

 those of Clitellaria. 

 This genus may be distinguished from Culcua by the shape of the 

 abdomen. 



17. Nerua scENOPiNoiDES, u. s. F(£m. Atra, nitens, antennis fulvis, 

 scutelli spinis pedibusque albis, alis nigrocinereis, postice pallidiori- 

 bus, venis nigris, halteribus testaceis. 



Female. Coal-black, shining ; antennae tawny ; thorax slightly to- 

 mentose ; spines of the scutellum and legs white ; wings blackish 

 grey, paler towards the hind border, veins black; halteres testa- 

 ceous. Length of the body 3 lines ; of the wings 5 hnes. 



6* 



