52 CALIFORNIA ACADEMY OF SCIENCES. [PROC. 3D Ser. 



1. Front metallic violet 2 



Front not metallic violet 5 



2. Fore tibiae incrassated 3 



Fore tibiae not incrassated 4 



3. Second joint of fore tarsi tipped with a long bristle. 



fortunatus, sp. nov. 

 Second joint of fore tarsi without a long bristle.. z'*?^^/?^^, sp. nov. 



4. All the coxae yellow .frontalis LoEW. 



Only the tips of the fore coxae yellow sobrinus, sp. nov. 



5. Arista with a pointed tip Oreas, sp. nov. 



Arista with a dilated tip nodatus, LoEW. 



51. Nothosympycnus fortunatus, sp. nov. 



Plate III, Figs. 83-85. 



Male. Length 3.25 mm.; length of wing 3 mm. Proboscis and palpi 

 piceous, tipped with yellow. Face extremely narrow, so that the eyes 

 almost meet, covered with light gray dust. Antenna long, dark brown; 

 first joint cylindrical; third joint large, oval, evenly rounded anteriorly, 

 pilose; arista inserted near its base on the dorsal side, as long as the head 

 and proboscis, black, finely and densely plumose on either side, tip some- 

 what broadened. Front brilliant metallic violet; circumocellar region velvety 

 black in some lights. Postocular cilia conspicuous, black above, pale below. 

 Thorax dull black, covered with brown dust except on a median vitta- 

 shaped area and on two roundish regions near the humeri; these three 

 regions appearing as dark spots. Scutellum bright metallic violet. Abdo- 

 men slender, laterally compressed, brownish black except the bases of the 

 first, second and third segments and the venter, which are light yellow. 

 Hypopygium very prominent, sessile but separated from the last abdominal 

 segment by a constriction; appendages brownish, posterior pair small and 

 hairy, anterior pair distinctly larger, blunt; penis scarcely longer than the 

 posterior appendages, rather thick, directed backwards; hairs covering the 

 abdomen and scape of the hypopygium black. Pleurae metallic blue green, 

 covered with white dust except near the humeri, where the shining green 

 ground-color is revealed. Coxae white; fore pair with delicate silvery white 

 hairs on their anterior surfaces; those of the middle and hind pairs each with 

 a black bristle on the outer side. Fore leg white, tibia distinctly swollen, 

 tarsi infuscated from the middle of the second joint; first joint very short and 

 somewhat incrassated, second joint nearly as long as the third, fourth and 

 fifth joints taken together, bearing near its tip on the upper side a long 

 slender bristle; third and fourth joints with several longer hairs on their 

 upper surfaces; fifth joint black. Middle femora white with a series of incon- 

 spicuous black cilia on the under side; middle tibiae and tarsi yellowish, the 

 latter infuscated from the tip of the first joint, which is considerably longer 

 than all the remaining joints taken together. Hind legs with basal third of 

 femur white, middle third yellow, apical third brown; tibiae yellow, infuscated 

 at the tip and rather bristly throughout; tarsi entirely dark brown, first joint 



