INTRODUCTION 5 
His first division was called ‘‘Tipulares’’ (renamed ‘‘ Nemocera’’ 
by Latreille in 1817) ; and his second division (to which Maecquart 
gave the name “‘ Brachycera’’ in 1834) was divided into 12 fami- 
les, one being the Muscidae. The Calliphoridae were included 
in the Muscidae. Latreille noted that the Muscidae and the 
Tipulidae have different types of pupae. 
Fallen (1814-1820) noted the presence of oral vibrissae in the 
Calypteratae and their usual absence in the Acalypteratae. 
Robineau-Desvoidy (1830 and 1863) may correctly be called 
the first specialist on the muscoid flies. He first used the character 
of the ptilinum, characters of head sclerites, bristles, simple 
proportion, and differences in venation, and he recognized the 
arista as having evolved from the fourth and terminal antennal 
segments of Nemocera. In his attempt to develop a natural 
classification he endeavored to make use of larval habits. He 
established many of the genera of Calliphoridae which are ree- 
ognized at-the present time. It is especially noteworthy that the 
work of Robineau-Desvoidy was apparently much ahead of his 
time, for it has been only within the past 40 years that an at- 
tempt has been made to credit him with his understanding of 
the natural relationships between the species of muscoid flies. 
Meigen (1838) noted that a transverse mesonotal suture is 
present in calypterate flies and that such a suture is incomplete 
in acalypterate flies. 
Characters in the mouthparts, wings, and antennae were 
‘chiefly used for classifying the major divisions of muscoid Dip- 
tera for nearly 100 years. These may have been satisfactory for 
the separation of genera and species in a limited area, but they 
certainly became of less value as new forms were discovered and 
described. 
Second period. The discovery by Mik and Osten Sacken that 
the arrangement of bristles on muscoid flies was relatively con- 
stant within a species, and the resultant systematic use of such 
bristling for taxonomic purposes, ushered in the second historical 
period. The combination of characters of bristling with those 
previously introduced allows an arrangement of genera and 
species which is somewhat similar to that now in general usage. 
Mik (1878) proposed the first system for classifying the bristles 
of the legs of muscoid flies. This system was amplified by Osten 
Sacken (1904), while Grimshaw (1905) later proposed an almost 
identical system, apparently independent of Mik and Osten 
Sacken. | ‘ 
Osten Sacken (1881 and 1884) first noted that the arrange- 
ment of bristles on the bodies of flies could be used as a means 
