36 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.64 



23. Valves of hypopygium very large, scoop-shaped, extending forward under abdo- 



men. (Costa Rica) hypopygialis, new species. 



Hypopygial valves hidden, circular. (Va.) lachnosternum, new species. 



24. Middle femora with two rows of outstanding flexor bristles. (Md.) 



setipes, new species. 

 Anterior row of flexor setae undeveloped 25 



25. Mesonotum paler in middle than on the brownish sides; wings nearly hyaline. 



(West Ind. ; Panama) lumbalis Williston, 



Mesonotum ferruginous, at most the scutellar region darker; wings with vague 

 apical clouding. (S. and C. Amer.) ferruginea Czerny. 



53. SOBABOCEPHALA ANNULATA, new species. 



(Fig. 34.) 



Male. — Front pale yellowish, ocellar dot shining black, face and 

 cheeks whitish, the bucca runmed with black; moiithparts and an- 

 tennae yellowish white, the finely plumose siibapical arista black; 

 all bristles on head blackish and longer than usual, buccal hairs all 

 small. Thorax shining, variegated yellow and black, mesonotum 

 with a broad shining central spot extending back to meet the black 

 scutellum, metanotum brownish with a large black spot on either 

 metapleura, mesopleurae largely black; posterior dorsocentral strong, 

 two pairs of basal scutellar setae, notal hairs black. Abdomen black 

 except at extreme base, hypopygimn small. Legs yellowish with 

 black bristles, the femora with central black annulus, posterior flexor 

 bristles of front femora strong. Wings twice as long as wide, smoky 

 on outer half, costa vanishing at third vein, costal ratio 3.5 : 1.6 : 1, 

 sections of fourth vein 1 : 1 : 2, of fifth vein 3:1, second vein strongly 

 diverging from third; calypteres pale with black edge and fringe; 

 halteres whitish. Length 3.5 mm. 



Female. — Head luteous, a medial vitta sometimes extending along 

 front and face, antennae deep yellow. Abdomen with last segment 

 and ovipositor whitish. All tibiae and front tarsi blackish. Length 

 4,5 mm. 



Types. — Seven males and five females, Turrialba, Costa Rica 

 (Schild) in Melander collection, A female from the National Museum, 

 Cat, No, 26267, U,S.N.M., collected by August Busck at Porto 

 Bello, Panama, is considerably darker; the front and face are smudgy, 

 the black spot of notum connects with the prealar pleural spot, and 

 the femora are largely blackened, 



54. SOBABOCEPHALA BISTRIGATA Eertesz. 



(Fig. 33.) 



Sobarocephala bistrigata Kertesz, Ann. Mus. Hung., vol. 1, p. 572 (1903) . 

 Heteroneura xanthops Williston, in part, Trans. Ent. Soc. Lond., 1896, p, 386 

 (1896).— Czerny, in part, Wien. ent. Ztg., vol. 22, p. 100 (1903) 



Ochraceous, posterior sides of notum black, scutellum, metapieurae 

 and abdomen except base and apex black; legs yellow, the front 



