Diptera of 8t. Vincent {West Indies). 421 



Scutellum reddish, blackish at the base, its straight distal margiu 

 •with two rather remote bristles. Pleurae reddish-yellow. Abdomen 

 elongate ; shining black, at its base obscurely reddish. Legs yellow, 

 the hind tibia; somewhat, and the last two joints of the tarsi, brown. 

 Wings nearly hyaline; third section o£ the costa as long as the 

 second section. Length 2| mm. 



One specimen. St. Vincent. 



OsciNis. 

 Latreille, Nouv. Diet. d'Hist. Nat., xxiv., 196, 1804. 



1. Scutellum elongated, triangular, pointed 2 



Scutellum oval, convex 3 



2. Scutellum wholly light-yellow; mesonotum black in the 



middle, yellow on the sides .... ti-iangiilarix^ n. sp. 

 Scutellum black, yellow at the tip ; mesonotum wholly 



black apkxtli-f, n. sp. 



3. Second section of the costal vein not twice the length of 



the third 6 



Second section of the costal vein fully twice the length of 



the third 4 



4. Antenna; yellow >> 



Antennae black fui,n. sp. 



5. Mesonotum black, greyish-yellowish dusted . . incqjien-i, n. sp. 

 Mesonotum yellow, with four narrow brown stripes, 



quadrilineufa, n. sp. 



6. Thorax yellow, shining m/tis, n. sp. 



Thorax not shining, yellow 7 



7. Thorax shining black, front mostly shining black .... 8 

 Thorax opaque, vittate ; front opaque nana, n. sp. 



8. Front tarsi yellow ; scutellar bristles approximated, third 



joint of the antennte largely yellow . . . concinna, n. sp. 

 Front tarsi black ; antennae black uaonyma. 



1. Osiinis triangularis, n. sp. (PI. XIV., fig. 153a, wing.) 



^ , ^ . Eyes densely pubescent. Front narrow, not one-third 

 of the width of the head ; opaque yellow, a minute black spot at 

 the ocelli ; the small frontal triangle shining. Antennae yellow. 

 Face, the narrow cheeks, the palpi, .and the proboscis light-yellow. 

 Thorax light-yellow, with light-yellow hair ; mesonotum with 

 three broad, coalesced or coalescent black stripes, the middle one 

 of which extends further forward than the others. Pleurfe with a 



