226 MR. T. WALKEE ON DIPTERA COLLECTED IN 



der, about six times the length of the 2n(l. Thorax with a silvery 

 stripe, which is attenuated in front ; sides and pectus silvery. Abdo- 

 men with a chalybeous tinge, more than twice the length of the 

 thorax ; 2nd, 3rd, and 4th segments with broad deep-black bands on 

 their hind borders ; 3rd and 4th with whitish fore borders. Legs 

 long. Wings narrow, cinereous, black along the costa and along the 

 borders of the veins ; prsebrachial vein much carved at its flexure, 

 straight thence to the tip ; discal transverse vein curved inward, 

 parted by less than half its length from the border, and by less than 

 its length from the flexure of the praebrachial vein ; alulae whitish 

 cinereous. Length of the body / lines; of the wings 12 lines. 



21. DoLESCHALLA GONYPEDoiDES, n. s. Mas. Obscurc fusca, capite 

 argenteo, frontalibus atris, antennis nigris basi fulvis, abdomine lon- 

 gissimo maculis octo lateralibus conicis chalybeo-testaceis, pedibus 

 nigris longissimis, ahs obscure cinereis, costa venisque nigricante 

 nebulosis. 



Male. Dark brown. Head silvery white ; frontalia deep black, widening 

 in front. Proboscis, palpi, and antennae black ; the latter not reach- 

 the epistoma, tawny at the base. Thorax cinereous along the sutures ; 

 sides and pectus whitish. Abdomen thrice the length of the thorax, 

 with four large conical testaceous chalybeous-tinged spots on each 

 side. Legs black, very long. Wings dark cinereous ; costa and 

 borders of the veins blackish-clouded ; praebrachial vein very near 

 the border, and emitting a short branch at its flexure, near which it is 

 curved inward, straight thence to its tip ; discal transverse vein un- 

 dulating, parted by much less than half its length from the border, 

 and by a little more than its length from the flexure of the praebra- 

 chial vein ; alulae pale cinereous. Length of the body 9 lines ; of the 

 wings 12 lines. 



Gen. Peosena, St. Farg. 



22. Prosena pectoralis. Walk. See Vol. IIL p. 101. 



Female"? Blackish. Head silvery white ; frontalia deep black, slightly 

 widening in front. Antennae tawny, not reaching the epistoma. Thoivix 

 with two whitish stripes ; sides and pectus white. Abdomen oval, 

 whitish, with long stout bristles; a deep-black band on the hind 

 border of each segment. Legs black ; coxae and femora tawnv, 

 the latter with black tips. Wings cinereous, diffusedly and indis- 

 tinctly brownish-bordered along the veins ; praebrachial vein forming 

 an obtuse angle at its flexure, very slightly curved inwards thence 

 to the tip ; discal transverse vein slightly undulating, parted by half 

 its length from the border, and by less than its length from the 

 flexure of the praebrachial vein. 



There are two errors in the description referred to above. The s])eci- 

 men there characterized is a male, and is not a Dexia. 



