42 A REVISION OF THE NEARCTIC SCIOMYZIDAE 



and middle and hind tibiae pale; pleura with distinct brown stripe 

 from below humeri to base of abdomen. 



The species of our fauna are grouped into three subgenera, which 

 are more fully discussed in their places below. 



Key to the Species of Melina 



1. Wings fuscous, with numerous isolated diluted spots guttata 



Wings hyaline, with isolated fuscous spots or cloudings 2 



Wings hyaline, with at most only the cross-veins or longitudinal veins 



clouded 5 



2. Marginal cell clouded beyond first 3 



Marginal cell clouded only at extreme apex; first and second veins pale; 



third to fifth dark and clouded; pale yellow species albocostata 



Marginal cell with several isolated fuscous spots maculata 



3. First posterior cell broadly clouded apically; costal cell conspicuously white. 



albovaria 

 First posterior cell without any fuscous band; costal cell not white; sec- 

 ond posterior cell with appendage from fourth vein tenuipes 



Submarginal and first posterior cells with a subapical fuscous band 4 



4. Submarginal cell with several fuscous spots basad of the subapical band. 



strigata 



With only the subapical band fuscous nana 



.5. Mesofrontal stripe distinct, narrow, subopaque, and more or less com- 

 plete 6 



This stripe absent or represented only by the gray attenuation of the 

 ocellar triangle 7 



6. Antennae entirely tawny; wings with clouded cross-veins trivittata 



Antennae dark apically; cross-veins not clouded grisescens 



7. Frons with only one frontal bristle; mesopleura entirely setulose; pro- 



pleural bristle microscopic Atrichomelina pubera 



Frons with two frontals; me.sopleura at most setulose along the jiosterior 

 margin 8 



8. Mesopleura entirely bare 9 



Mesopleura with posterior margin setulose; robust, dark ferruginous 



species spadix 



9. Dark species 10 



Pale species albocostata 



10. Anterior frontal bristle midway between the other frontal and anterior 

 margin of frons; second posterior cell with ai)pendage from fourth vein. 



tenuipes 



Anterior frontal much nearer the other one; rarely with ajjpendagc in 



second posterior 11 



11. Fore tarsi entirely black vitalis 



Fore tarsi pale basally similis 



