1924] 
Review of the Dipterous Family Piophilidce 
83 
Five species not represented in my collection are omitted since 
their descriptions are too brief to show phyletic location in the 
key. The omitted species are : P. concolor, a red species probably 
a Cordylurid; nitens, perhaps a Pseudodinia; senescens, vaguely 
recorded by Macquart in 1851 as from North America and not 
since recognized, possibly not Piophila since it is gray pubescent; 
and the Greenland hairy species pilosa and nigerrima. 
Key to the Subgenera and Species of Piophila. 
Mesonotum finely scabrous, centrally not pubescent but with 
three rows of setulse, one in the middle and one on each 
dorsocentral row; fronto-orbital, humeral, presutural and 
sternopleural bristles undeveloped; ocellar bristles small, 
widely distant and located opposite the front ocellus, the 
ocellar triangle differentiated as a shining space on the 
satiny front; vertical bristles small; mesopleurse sparsely 
hairy; pygidium transverse, retracted within the fifth 
segment and asymmetrically excised toward the right side; 
cheeks more than half the eye-height; second and third 
joints of front tarsi subequal to metatarsus. Subgenus 
Piophila Fallen, s. str. Genotype and only American 
species, cosmopolitan. casei Linn. 
Mesonotum smoothly polished and uniformly pubescent; ocellar 
bristles located behind the front ocellus; cheeks less than 
half the eye-height; sternopleural bristles usually present, 
though small; front metatarsi longer than two following 
joints together 2 . 
2 Fronto-orbital, humeral and presutural bristles minute or 
wanting; mesopleurse usually sparsely hairy; pygidium re- 
tracted and cleft toward the right side, i. e. the sixth segment 
displaced: lower occiput black or blackish, with a pruinose 
vertical stripe below the eyes abruptly stopping in a vertical 
line on the cheeks, (if occiput is shining, front blackened 
on upper three fourths, legs mostly black, and antennae 
dark above, see Prochyliza hrevicornis, n. sp.) Genotype P. 
nigriceps Meig. Subgenus Stearihia Lioy 3 . 
