ART. 11. FLIES OF THE FAMILY CLUSIIDAE MELANDER AND ARGO. 41 



arista nearly tliree times the antennal length and pubescent; front 

 decidedly narrowed above due to the bulging in of the eyes; bristles 

 small, brown, buccal hairs short. Mesonotum mostly black, a central 

 vitta and sutural spot yellowish, humeri and sides of mesonotum in 

 front of suture contrastingly white, scutellum whitish, metanotum 

 brown; pleurae shining yellow with two black spots, one directly 

 under humeri, the other behind the front coxae, metapleurae black; 

 presuturals present, one lateral scutellar seta located well up on the 

 disk, thoracic bristles brown. Abdomen black except at yellowish 

 base. Legs yellow except front tarsi and all tibiae which are black- 

 ish; flexor femoral bristles undeveloped, only tliree in posterior row 

 of front femora near knee. Wings nearly hyaline, a vague clouding 

 at apex and in distal half of discal cell, first and second veins yellow, 

 others black except at root; costal ratio 5 : 1.5 : 1, fourth vein 1:1: 

 2.5. fifth vein 2.5 : 1; halteres pale yellow. Length 4 mm. 



Type. — La Suiza de Turrialba, Costa Rica, collected during 

 August, 1921, by Pablo Schild; in Melander collection. 



Variations. — A female in the National Museum, Cat. No, 26271, 

 U.S.N.M., from the same collector repres.ents an extreme pale 

 variation. The genal spot is luteous, the black of the mesonotum is 

 reduced to a prescutellar spot medially excised in front and another 

 in front of the wings, the pleurae and metathorax are immaculate 

 yellow, the abdomen black only on the middle tergites, and the 

 tibiae have a faint brown ring below the knee. Another female, col- 

 lected by Dr. P. P. Calvert at Juan Vinas, Costa Rica, in the collec- 

 tion of the American Entomological Society, represents the other 

 color extreme. The upper sides of the occiput are black, the notum 

 and pleurae are wholly black except for the humeral-lateral white 

 mark and the white scutellum, and the clouding of the Avings is more 

 evident. Structurally the three specimens agree. 



65. SOBAROCEPHALA HYPOPYGIAUS, new species. 



(Fig. 41.) 



Male. — Front shining yellow, more opaque and luteous above 

 antennae, ocellar spot black, face and cheeks white, the genae silky; 

 mouthparts and antennae yellowish, the latter brown above the 

 black plumose arista ; bristles of head long and brown, four long buccal 

 hairs. Notum shining ochraceous with two narrow parallel very faint 

 brownish dorsocentral stripes reaching from center of mesonotum to 

 tip of scutellum, notal hairs and bristles black, prescutellars lacking, 

 two lateral scutellar setae; pleurae pale yellow, mesosternal hairs 

 long. Abdomen black-bristly, yellowish brown, hypopygium yellow- 

 ish and unusually large, the valves very large and scoop -shaped 

 extending forward under the abdomen and almost reaching the base., 

 Legs yellowish, hairs black, front tarsi brownish, front femora with 



