386 Professor Williston on the 



inclined to identify this species with S. grata from 

 Brazil, but the brief description shows such discrepancies 

 that it is hardly possible that the species are identical. 

 Possibly it is S. octojmncta. 



HETERONEURID^. 



Hetergneura. 

 Fallen, Agromyzidfe, 1823. 



1. Thorax black 2 



Thorax in large part yellow 3 



2. Tip of antennse black flavipes, n. sp. 



Antennse wholly yellow concinna, n. sp. 



3. Wiags cinereous hyaline 4 



Wings in large part brown 5 



4. Mesonotum wholly yellow in front lumbalis, n. sp. 



Mesonotum black on the sides in front .... valida, n. sp. 



5. Mesonotum and scutellum black j^Zeura/is, n. sp. 



Mesonotum and scutellum in large part yellow xanthops, u. sp. 



1. Heteroneura xantJiops, n. sp. 

 ^,5- Head, including the proboscis, wholly yellow; front 

 and face of equal width, the former widened near the vertex only ; 

 arista black, long pubescent or short-plumose. Mesonotum shining 

 black on the sides, a broad stripe, about one-third of the whole 

 length, beginning at the neck and running to the tip of the 

 scutellum, light-yellow, the sides of the scutellum brown or 

 brownish. Pleurae, pectus, and coxee pure light-yellow, lighter 

 than the yellow of the mesonotum. Abdomen black or dark- 

 brown, the basal segments yellowish, the thickened under portion 

 of the hypopygium yellow. Legs yellow, the tarsi slightly 

 brownish ; middle tibife with a stout spur and a preapical bristle. 

 Wings clouded with brown on the distal half, less strongly so on 

 the proximal portion ; penultimate section of the fourth vein one- 

 fourth or one-fifth the length of the ultimate section, and shorter 

 than the last section of the fifth vein. Length 3-3^ mm. 



Five specimens. St. Vincent. A single female 

 specimen has the mesonotum black, except an elongate 

 yellow triangle reaching nearly to the scutellum, the 

 metanotum black, and the abdomen black. Several 

 males have the black of the mesonotum beginning 

 further back, and the whole hypopygium yellow. It is 

 not improbable that there are two distinct species here. 



