256 Professor Williston on tlie 



in the first basal cell. Length 4-5 mm. ; of the antennas, male, 

 16 mm. ; female, 7 mm. 



$. Head light yellow, the ocelli black. Antenn93 about four 

 times the length of the body ; brownish, toward the base brownish- 

 yellow. Palpi brown. Mesonotum yellow, with three brown 

 stripes, the middle one extending to the collar, the lateral ones 

 abbreviated in front and turned downwards to connect with a 

 vertical brown stripe on the pleurae. Pleurae light yellow, with a 

 brown spot in front of the halteres, in addition to the vertical 

 Stripe, which extends to the middle coxae. Scutellum and meta- 

 notum brown. Abdomen yellow, the proximal segments some- 

 what inf uscated toward their base ; hair black. Legs light yellow ; 

 tarsi inf uscated ; front tibiae suddenly dilated at their tip. Wings 

 cinereous hyaline ; a dark brown spot at the junction of the third 

 and fourth veins, extending back to the angle of the posterior 

 basal cross-vein ; a similarly coloured spot at the tip of the first 

 vein, reaching across the third longitudinal vein ; the tip of the 

 wing is broadly brownish, and there is a small brown spot in front 

 of the fourth vein, opposite the tip of the auxiliary vein ; anterior 

 cells yellowish ; anterior branch of the third vein oblique and 

 pallid. 



5 . In the single female specimen, the colour is more reddish- 

 yellow, the abdomen is red with the posterior margin of the 

 segments yellow. Antennae only about twice the length of the 

 body. 



Seven specimens. Sea level, and ]000 feet. This 

 species seems to be related to M. inconcinna, Loew, but 

 differs especially in the markings of the thorax. 



Platyura. 

 Meigen, Ilhger's Mag., ii., 264, 1803. 



Table op Species. 



1. The anterior branch of the third vein terminates in the 



first longitudinal vein parva, n, sp. 



The anterior branch of the third longitudinal vein termi- 

 nates in the costa beyond the end of the first vein . 2 



2. Wings with brown spots inctipennis^n. ^^. 



Wings uniformly inf uscated 3 



3. Auxiliary vein very short ignohilis^ n. sp. 



The auxiliary vein terminates opposite the origin of the 



third longitudinal vein fafidventrisj n. sp. 



