SuBFAMILY CHRYSOMYINAE 143 
Distribution. Widely distributed in the Nearctic and Neo- 
tropical regions, from southern Canada throughout the United 
States, Mexico, the West Indies, Central America, and South 
America southward to Chile and Argentina. 
Certain variations in coloration occur. Northern specimens 
often have considerably less orange-red color than southern 
specimens, while specimens from southern states or from the 
tropics are rather greenish in certain lights when freshly col- 
lected. Adults from relaxing jars are usually more metallic blue 
to purple than adults in nature. The typical coloring of the 
legs is yellow orange to red orange, never black. It is possible 
to produce most of these variations in macellaria by varying 
humidity and temperature during the immature stages. 
Aldrich indicated that the three specimens of this species 
which are in the museum at Copenhagen are probably not the 
Fabrician types, but these specimens were accepted as types by 
Townsend. Both Aldrich and Townsend agreed that they repre- . 
sent the species now known under this name. 
Synonymy of macellaria by older authors cannot be accepted 
without question and relatively few names previously listed as 
synonyms have been found actually to refer to this species. Some 
of the names listed above as synonyms of macellaria were so 
identified from type specimens in European museums by Aldrich 
in 1929, but the synonymy may not be correct in all eases, for 
Aldrich was not aware at that time of the existence of americana; 
he often identified the latter species under the name of Paralu- 
cilia fulvipes (Macquart). 
Biology, habits and wmmature stages. Egg. Deposited in a 
yellowish, rounded, loosely cemented, irregularly flattened mass, 
the average number in a single mass being from 40 to 250 eggs 
(maximum observed, 1,228). The individual egg is approxi- 
mately 1 mm. in length and 0.2 mm. in diameter, smooth, glist- 
ening whitish, rounded at posterior end and somewhat flattened 
at anterior end, with a narrow dorsal longitudinal band or seam, 
the narrowness of which causes the cap to appear small. 
When live animals are blown by this species, the egg masses 
are usually deposited among wool or hair in irregularly arranged 
patches and loosely or not at all attached to the skin. Such egg 
masses may be composite depositions from several females, and 
a suitable location near an attractive wound may contain thous- 
ands of macellaria eggs. 
The incubation period is approximately half that required for 
americana. Melvin (1934) found almost 33 hours were required 
for incubation at 64° F. and that few eggs hatched at tempera- 
