40 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
has previously been noted; it is by no means prominent. The pos- 
terior femur varies from spindle-shaped to cylindrical. On the an- 
terior face are several rows of bristles; three is undoubtedly the 
normal number, one borne on the upper portion of the face, one 
slightly beneath it, and one at the bottom. When the normal num- 
ber is present, these are respectively referred to as the upper, inter- 
mediate, and lower rows. When more are present there may be two 
or even three intermediate rows, and sometimes two lower rows as in 
Ravinia comviiinis. These are also designated as the first, second, 
third, etc. Except in Boettcheria the bristles of the upper and lower 
rows are always the longest and stoutest. In other genera, so far as 
noted those of the intermediate rows are short, vestigial, or wanting, 
and not complete {i. e., do not extend the full length of the femur). 
The lower row is almost lacking in Sarcophaga fukipes Macquart and 
S. fulmpcs nigra; in Boettcheria it is represented by widely separated 
bristles on the distal half or third. A lower row may be present on 
the posterior face but it is never very strongly developed. On the 
middle femur of Sarcophaga sinuaia Meigen an oval, golden, yellowish, 
or sometimes whitish spot is found on the distal third of the anterior 
face, and a similar much smaller one in the center of the posterior 
surface. I doubt if this is absolutely constant, however. The ven- 
tral surface of the femur typically bears an anterior and a posterior 
row of bristles. These have been diversely modified. In Boettcheria 
the posterior row is absent, the anterior represented by a few short 
bristles at the center; in Ravinia, both rows are complete; in Sarco- 
phaga their characters are varied. Distally the posterior row often 
consists of short, stubby, or sometimes spine-like bristles, called the 
'comb' (Kamm, Bottcher). In our species of the haemorrhoidalis 
group the 'comb' is the only part of the row present; in Ravinia 
qiiadrisetosa (Coquillett), R. latisetosa, and species of the assidua group 
(Sarcophaga) it is confined to the very distal portion and composed 
of but a few bristles. Of course it is absent in Boettcheria. Other 
bristles than those mentioned that occur on the posterior and middle 
femora, are of no value. The anterior femur has three rows of bristles 
on the posterior surface; the intermediate is always the smallest and 
in some species of Sarcophaga very much reduced. The vestiture of 
the tibiae may be entirely of short hairs; the posterior, however, are 
often horded on their anterior and posterior faces. The beards may 
consist of very long, closely set, even bristly hairs or the latter may be 
