TAXONOMY OF MUSCOIDEAN FLIES — TOWNSEND 27 



cates above great central foramen; cerebrate of Rob.-Desv. ; epicephalon of 

 Lowne). 



1)2) Occipito-cextral bristle (do. of Hough ; small bristle on parafrontal- 

 occipital ridge just below inner vertical bristle before bifurcation of ridge) 

 present or absen£, character of. 



1)2) Occipito-laTERal bristle (do. of Hough; small bristle on occiput just 

 below outer vertical bristle) present or absent. 



2) Occipital area (the characteristic hairy area of occiput which some- 

 times invades the cheeks posteriorly) invading cheeks, or restricted to occiput. 



2) Longitudinal diameter of occiput (shows its degree of swelling at any 

 specified point) above or below compared with eye width in profile. 



2) Beard (pilosity arising and depending from lower portion of occiput, 

 and in certain cases clearly defining a portion of cheeks invaded by occipital 

 area') long, short, thick, thin. 



(Thorax) 



1)2) Sternopleural bristles one, two, three, or more, in what arrangement. 

 1) HypoplEural bristles strong, weak, or represented only by hairs. 

 1) PteroplEural bristles strong, weak, or hair-like. 



MesoplEural bristles very strong, or normal. 



1) ProplEural bristles strong, weak, number, direction. 



1 1 NotoplEural bristles (postliumeral of Osten-Sacken) strong, weak, 

 number. 



2) Postsutural bristles (dorso central of Girschner behind suture; outer 

 dorsocentral of Osten-Sacken behind suture) strong, weak, relative strength, 

 number, position. 



2) Dorsocentral bristles (dorsocentral of Girschner before suture; outer 

 dorsocentral of Osten-Sacken before suture) strong, weak, relative strength, 

 number. 



i 12) Acrostichal bristles (2 middle rows both before and behind suture) 

 strong, weak, number, position. # 



2) Humeral bristles strong, weak, number, direction. 



1) Intrahumeral bristles (postliumeral of Girschner) present or absent, 

 number, position. 



1) Presutural bristles (+ postliumeral of Girschner = intrahumeral of 

 Osten-Sacken) strong, weak, position in relation to preceding. 



1) Intraalar bristles strong, weak, whether one in front of suture. 



2) Supra Alar bristles (+ postalar = supraalar of Osten-Sacken) strong, 

 weak, number. 



2) Postalar bristles strong, weak, number. 



1)2) Scutellar bristles strong or weak, comparative strength of the vari- 

 ous pairs, number of lateral pairs ; a weaker apical pair present or absent, 

 erect, suberect, directed posteriorly, decussate, or divergent; discal pairs 

 present or absent. 



(Wings) 



2) Wings broad, long, narrow, short; costal margin swollen or dilated in 

 male, or in both sexes, or normal. 

 2) Costal spine distinct, strong, weak, double, or absent. 

 2) Longitudinal veins bristly, to what extent, or bare. 



