136 Mittheil. d. Münchener Ent. Ver. 1881. 
several bristles on the humeral callus, two posthumeral, on 
the praesutural triangular depression, and a few other bristles, 
inserted in the interval between the humeral callus, the prae- 
sutural depression and the outer row of the dorso-central 
region; these bristles I have called the znira-humeral bristles. 
In the Anthomyina there are usually only two such bristles; 
one of them seems to be the homologue of the praesutural 
bristle of the Acalyptrata, and is inserted immediately above 
the praesutural depression, the other is in front of the former, 
near the humeral callus. In Calliph. erythrocephala , Lucilia 
caesar etc. I perceive four such bristles, that are more con- 
spicuous than the others; three along the praesutural depres- 
sion, the fourth near the humeral callus. 
The dorso-alar region contains (usually) two, posterior 
swpra-alar bristles, inserted on the post-alar callus; the second _ 
of them, as usual among the Acalyptrata also, is placed: im- 
mediately above the alar frenum; and a row of anterior supra- 
alar bristles, three or more, along the edge of the anterior 
supra-alar cavity. The other bristles of this region may be 
called the intra-alar bristles and form a longitudinal series of 
two or tlree, between the supra-alar bristles and the outer 
row of the dorso-central. They sometimes form a spurious, 
irregular row or series with the intra-bumeral bristles of the 
dorso-humeral region. 
The passage from hairs to bristles is to gradual among 
. the Calyptrata, that the number of bristles of a given 
kind is sometimes difficult to state, and sometimes variable 
in the same species, adventitious hairs assuming the propor- 
tions of bristles. The more hairy a species is, the more it 
seems liable to such variations, 
In the Oestridae, as an exception, the differentiation 
between the Macrochaetae and ordinary hairs is feebly deve- 
loped in some genera and not at all in others. 
_ Borsten“ that pair of rows which in reality is the outer. This is one of 
those cases where it seems to me a change in the nomenclature adopted 
by former authors becomes unavoidable. 
e: 
# 
“ 
rd 
