304 Annals Entomological Society of America [Vol. VII, 
of the second segment. These, however, disappear after the 
larva has made two or three moults, and there are no longer 
any anterior spiracles. 
At the extreme tip of the first segment, on either side of the 
great hooks, there is a pair of wartlike processes, as shown in 
text-fig. 1. These are probably rudimentary antenne. 
Internal Anatomy. The alimentary canal and Malpighian 
tubules, (shown in Plate XL, Fig. 1.) are quite characteristic, in 
their many turns and loops, of Dipterous larve in general, 
especially those of the Muscid kinds. The parasitic life of the 
larva seems to have resulted in no considerable structural 
modification of the digestive system. 

Fig. 2. 
Adult fly, dorsal view, showing general characteristics; also lateral view of 
head, showing proboscis with two geniculations, one near the base and the other 
near the middle. (Greatly enlarged). 
The oesophagus, starting at the mouth, extends backward 
as a narrow cylindrical tube, passing through the supracesopha- 
geal ganglia, or brain, and then passing above the ventral 
ganglion and entering the proventriculus, which lies in about 
the fourth segment of the body. From the proventriculus, the 
mesenteron, or portion of the canal from the proventriculus to 
