296 
Hominoxious Arthropods 
h. Arista terminal; hind metatarsus enlarged, sometimes orna¬ 
mented, hind tarsus more or less flattened beneath. 
. PLATYPEZID® 
hh. Flies having a different combination of characters. 
i. Head large, eyes occupying nearly the entire head; cell 
R 4 -j- s narrowed in the margin; small flies . .Pipunculid/E 
ii. Head and eyes not unusually large. 
j. Squamae (tegulae, or calyptrae, or alulae) not large, often 
quite small, the lower one lacking, or at most barely 
projecting from below the upper one (antisquama); 
front of both male and female broad, the eyes therefore 
widely separated; posthumeral and intraalar macro- 
chaeta not simultaneously present; thorax usually 
without a complete transverse suture; postalar callus 
usually absent; the connectiva adjoining the ventral 
sclerites always visible; hypopleural macrochaetae 
absent; last section of R4+5 and Mi+o with but few 
exceptions nearly parallel; subcostal vein often wanting 
or vestigial or closely approximated to Ri; the latter 
often short, basal cells small, the posterior ones often 
indistinct or wanting; vibrissae present or absent 
. Acalyptrate muscoidea 
k. Subcosta present, distinctly separated from Ri at the 
tip; Ri usually ends distad of the middle of the 
wing; the small basal cells of the wing distinct. 
I . A bristle (vibrissa) on each side of the face near the 
margin of the mouth. Cordylurid®, Sepsid®, 
Phycodromid®, Heteroneurid®, Helomyzid®. 
II . No vibrissae present. 
m. Head nearly spherical, cheeks broad and re¬ 
treating; proboscis short; the cell R5 closed or 
narrowed in the margin; legs very long; tarsi 
shorter than the tibiae. Calobata and other 
genera . Micropezid® 
mm. Flies with another combination of characters. 
Rhopalomerid®, Trypetid®, Ortalid®, 
SciOMYZin®. 
kk. Subcosta absent or vestigial, or if present, then 
apparently ending in the costa at the point where 
Ri joins it; Ri usually ends in the costa at or before 
the middle of the wing. 
I . Arista long plumose, or pectinate above; oral vibris¬ 
sae present; anal cell complete; costa broken at 
the apex of Ri. Drosophila, Phortica, and other 
genera. Drosophilid® 
II . With another combination of characters. 
m. The cell M and first M2 not separated by a cross¬ 
vein; anal cell absent; front bare or only 
