34 PriOCEEDINGS OF THE NATIONAL MUSEUM. vol.64 



mislead, Kertesz erected the genera Meriza and Monorrhexa for 

 those species possessing preapicals, Monorrhexa was proposed for a 

 species lacking prescutellars and having but four scutellars, and 

 Meriza for the species having prescutellar setae and six scutellars. 

 These characters are too inconstant to have generic value. Soharo- 

 cephala is apparently the dominant neotropical genus. 



KEY TO THE SPECIES OF SOBAROCEPHALA.' 



1. Wings with a large dark isolated spot around anterior crossvein 2 



Wings vsith apical spot or extended clouding or uniformly subhyaline, butwith 



no special mark around anterior crossvein 3 



2. Front less than one-third width of head; thorax with large posthumeral and 



supraalar spots, sctutellum black; wings with broad apical cloud, the cloud 

 over the anterior crossvein connected with the cloud over the posterior cross- 

 vein. (Brazil) finnilaei Frey. 



Front one-third the width of the head; thorax with black supraalar and usually 

 without posthumeral spots, scutellum largely or wholly yellow; wings with 

 apical cloudings at ends of veins, the clouds over the crossveins disconnected . 

 (Peru; C. Amer.) rUbsaameni Czerny. 



3. Arista densely bushy plumose; apex of wing and posterior crossvein blackish 4 



Arista loosely plumose or pubescent, at most bushy on basal half; apical infuma- 



tion of wing extended or absent; posterior crossvein not markedly clouded; 

 male lamellae usually rounded; thorax scarcely spotted or the spots large 5 



4. Notum and pleurae marked with several black streaks; hind femora centrally 



and middle femora at extremities black, tarsi pale; a distinct cloud over pos- 

 terior crossvein ; lamellae long and ham-shaped. (Costa Rica). 



variegata, new species. 

 Mesonotum marked with six spots, pleurae luteous; femora yellow, front tarsi 

 black; cloud over posterior crossvein weak; lamellae minute. (Panama.) 



plumata, new species. 



Mesonotum marked with broad black stripe tapering in front and extending 



laterally as curved brown band, abdomen with central vitta; femora yellow, 



tibiae and tarsi brownish . (Surinam) pictipennis Kertesz . 



5. Front decidedly narrowed above due to the bulging in of the eyes 6 



Sides of front nearly parallel; humeri not contrastingly white; arista plumose 7 



6. Entirely yellowish, including bristles and legs; arista openly plumose. (Eastern 



U.S.) convergens Malloch. 



Thorax mottled, humeri contrastingly white; tibiae darker than remainder of legs; 

 arista pubescent. (Costa Rica) humeralis, new species. 



7 . Mesonotum entirely black 8 



Mesonotum more or less yellowish 10 



8. Pleurae concolorous with notum; sections of fourth vein 1:6. (W. Ind.) 



concinna Williston. 

 Pleurae light yellow 9 



9. A brownish spot reaching down on pleura before wings; front yellow; sections of 



fourth vein 1:6. (W. Ind.) pleuralis Williston. 



Pleurae entirely yellow; front largely black; sections of fourth vein 1:3. (Costa 

 Rica) nigronotum, new species. 



10. Mesonotum with blackish marks 11 



Mesonotum yellow, at most blackish in the scutellar region^ 21 



11. All femora centrally more or less blackish; meso- and metapleurae largely black. 12 

 Femora not annulate; pleurae entirely yellow, at most the metapleurae black. .13 



1 5. Flaviseta is not included, see couplet 10. ' Cf. flaviseta Johnson if head bristles yellowish. 



