392 Professor Williston on the 



DlSCOMYZA. 



Meigen, System. Beschr., vi., 76, 1830. 



1. Discomyza duhia, n. sp. (PI. XIIL, figs. 138, wing; 

 138a, head of 6.) 



$ . Black, shining. Front, broad above, narrowed below; smooth, 

 the elongated vertical triangle metallic-green and finely punctulate ; 

 the anterior part of the front flattened. Antennae black, the third 

 joint rounded, and with rather long whitish pile on its upper side ; 

 arista with seven rays ; spine of the second joint moderately strong. 

 Face much narrowed a little above its middle, gently convex from 

 side to side and vertically, the lower part much receding, and the 

 oral opening small ; in the middle finely punctulate ; on the sides 

 with coarse wrinkles for its whole length ; moderately shining, not 

 dusted, its bristles short and small. Clypeus large, much receding, 

 cheeks narrow. Abdomen flattened, ovate ; fourth segment much 

 longer than the preceding. Halteres nearly white. Legs black, 

 the posterior tibise and all the tarsi, save the distal two joints, yellow. 

 Wings tinged with brownish ; third section of the costal vein 

 short, not more than one-third of the length of the second section ; 

 penultimate section of the fourth vein not one-half the length of 

 the ultimate section. Length 2 mm. 



Numerous specimens. St. Vincent. This species, in 

 its small oral opening and large clypeus, is rather 

 aberrant. 



PSILOPA. 



Fallen, Hydromyzidoe, 1820. 



1. Face shining black or metallic-green 4 



Face pollinose 2 



2. A minute blackish spot at the tip of the third vein, 



nigropimcta^ n. sp. 

 No spot at the tip of the third vein 3 



3. AntennEe red desmata, n. sp. 



Antennte black 7iigra, n. sp. 



4. Fi'ont tarsi deep black ; face shining black . . nigrimcma, n. sp. 

 Front tarsi yellow ; face shining green . . . aciculata, Loew. 



