ABT. 11. FLIES OF THE FAMILY CLUSIIDAE MELANDER AND ARGO. 3 7 



tibiae and tarsi and hind tibiae brown; arista closely plumose; wings 

 infumated on apical third and above fifth vein, sections of fourth 

 vein 1 : 3.5; length 3.2-4.3 mm. 



Distribution. — Originally described from Peru. Specimens from 

 Costa Rica, Jamaica, and St. Vincent, the last a cotype of Hetero- 

 neura xanthops Williston, have the scutellmn and metathorax yellow, 

 the antennae not brown at tip, the arista rather openly plumose, and 

 the hind tibiae less evidently brown. There is some variation in 

 size of hypopygium, the St. Vincent specimen having the hypopy- 

 gium very robust. 



55. SOBAROCEPHALA BIVITTATA, new species. 



(Fig. 36.) 



Front, face, antennae and mouthparts yellow, ocellar dot black, 

 cheeks whitish, arista black and distinctly feathery, bristles of front 

 brown, buccal hairs all small. The shining yellow mesonotum 

 bivittate wdth black, each vitta obliquely interrupted behind the 

 suture, the anterior spot reachmg along notopleural suture from 

 humeri to base of wing, the posterior stripe beginning near middle of 

 notum and extending exteriorly to dorsocentral rows to include sides 

 of the yellow scutellum; pleurae pale yellow, metanotum brownish, 

 metapleurae brown; notal hairs and bristles black, two lateral scu- 

 tellar setulae. Dorsum of abdomen ^vith a large central oval black 

 spot widest on fourth segment; hypopygium yellow, of medium size. 

 Legs yellow, with blacldsh hairs; front tarsi dusky, flexor setae of 

 posterior row of front femora nearly as long as femur-width and 

 black. Wings slightly cloudy on apical third, sections of costa 

 4.3 : 1.2 : 1, of fourth vein 1.2 : 1 : 3.8, of fifth vein 1.6 : 1; halteres 

 whitish. Length 3.5-4 mm. 



Types. — Seven specimens, Turrialba, Costa Rica, July (Pablo 

 Schild) in Melander collection, and four in National Museum, Cat. 

 No. 26268, U. S. N. M. The species is variable in extent of color, 

 the scutellum may be black or entirely yellow, the anterior thoracic 

 spot may encroach on the humeri or be almost obliterated, the meta- 

 thorax may be wholly yellow. S. histrigata and this species may 

 ultimately prove to be geographic races of one widely distributed 

 variable neotropical species. 



56. SOBAROCEPHALA CONCINNA Williston. 



Heteroneura concinna Williston, Trans. Ent. Soc. Lond., 1896, p. 387 (1896). — 

 CzERNY, Wien. ent. Ztg., vol. 22, p. 101 (1903). 



' ' Very much like H. Jlavipes, from which it differs in the antennae 

 being wholly light yellow, in the wings being nearly uniformly 

 blackish, except the immediate base, and especially in the presence 

 of distinct preapical bristles on the middle and hind tibiae. It is 

 also a little smaller." (Williston.) 



