1910] Thompson—Notes on Diptera 213 
and anterior part of the mesonotum which Mr. Townsend de- 
scribes as present in Oedemasoma nuda. Loew’s specimen is a 
female whereas Mr. Townsend’s is a male. In view of these facts 
it seems scarcely reasonable to separate them specifically. At 
Mr. Coquillett’s request I drew up a description of the type of 
Wahlbergia brevipennis Loew, and forwarded it to him for com- 
parison with the type of Oedemasoma nuda 'Towns., and he has 
come to the conclusion that the differences in the sex of the two 
specimens and the greased condition of Loew’s type were sufficient 
to account for the differences which exist between them. Mr. 
Coquillett considers that the generic reference to Wahlbergia was 
correct, so that the generic synonymy will stand as follows: 
Besseria Desvoidy, 1830. 
Wahlbergia Zetterstedt, 1842. 
Apostrophas Loew, 1870. 
Oedemasoma Townsend, 1908. 
In the other questions of synonymy discussed above Mr. Co- 
quillett substantially agrees with me, and I wish to express my 
gratitude to him for his kind and courteous assistance in this and 
many other matters. 
i: 
In the keys to the genera of the Sarcophagide and Muscidee 
in Williston’s ““Manual”’ there exists a slight but misleading error 
to which it may be well to call attention. If I do not mistake, 
these keys are adapted from those drawn up by Brauer and v. 
Bergenstamm in “Die Zweifliigler des k. k. Museums zu Wien.” 
As Mr. Townsend has already pointed out in his “Taxonomy,” 
the “genz”’ or “Wangen”’ of Brauer and v. Bergenstamm do not 
correspond to the “cheeks,” as the latter term is commonly under- 
stood, and as it is used in the keys to the Tachinide and Dexiidee 
in the “Manual,” but correspond to the “sides of the face”’ or 
“parafacials.”” The differences between the genera Calliphora 
and Lucilia, and between Phormia and Protocalliphora, are not 
in the presence or absence of hairs on the cheeks but on the sides 
of the face. Therefore, on page 343 of Williston’s “Manual,” 
the words “sides of the face,” or ‘“‘parafacials”’ should be substi- 
tuted for “cheeks,” in lines 2,5, 8 and 11, and the same correction 
should be made on page 351, lines 4, and 5. 
