464 N. E. McINDOO 
olfactory pores from hair sockets. As a rule, only the legs, wings, 
and halteres were examined, although in several instances the 
chitinous parts of the reproductive organs and the mouth parts 
were also examined, but usually no olfactory pores were seen 
on them. The sex of the species, except in a few cases, was not 
determined. 
a. Pores on legs. The disposition of the pores on the legs is 
more similar to that of those on the legs of Hymenoptera (Mc- 
Indoo, ’14 b) than to those on the legs of Lepidoptera or Coleop- 
tera (McIndoo, 715, 717). Pores were found on each trochanter 
and femur examined, but sometimes none was seen on a tibia and 
not one was ever observed on a tarsus. The distribution of them 
is similar to that of the house fly, already described. The total 
number of them varies considerably, depending on the number of 
groups present and the size of the species. The groups are usu- 
ally conspicuous and the one on the femur is quite characteristic ; 
it consists of two or three rows of pores variously arranged, 
depending on the genus examined. 
b. Pores on wings. The disposition of the pores on the wings 
is more similar to that of those on the wings of Lepidoptera than 
to those on the wings of Hymenoptera or Coleoptera. In Lepi- 
doptera the pores are well grouped, while in Diptera they are poorly 
grouped and consequently not much reliance can be placed upon 
the number of groups recorded; for this reason the variation in 
the number of groups need not be discussed. Lepidoptera have 
more isolated pores than have Diptera, and in the former order 
they may extend along the full length of the veins, while in 
Diptera they are never found farther than two-thirds the dis- 
tance from the base of the wing. The propterygium (fig. 2, 
Pr.) was often lost during the preparation of the integument, 
but group No. 8, was usually found on it whenever this part of the 
wing was present. This is the first time for this group to be 
reported. 
c. Pores on halteres. As already mentioned on page 462, there 
are four types of pores on the halteres, although the undeterminde 
type, consisting of large isolated pores, should be called isolated 
Hicks’ pores. The groups of Hicks’ pores are seen only with 
