28 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
Width of front: taken at the narrowest part of the front, the speci- 
men held head upward its longitudinal axis parallel with that of the 
binocular and the oral opening directed toward the standard. Repre- 
sented by the line ab, figure 33 (PI. 5). 
Width of eye: the greatest width is measured along a line cd 
parallel to a6. 
Height of eye: the distance eh measured on a line cf that is tangent 
to the upper eye orbit at the narrowest part of the front and passes 
across the mouth margin just anterior to the front limit of the cheek. 
For this measurement and the following the specimen is held at right 
angles to the position employed above. 
Height of cheek: also measured on ef and represented by the distance 
hf. 
Length of tarsal segments: measured from the base of a segment to 
the base of that which follows. On figure 23 (PI. 3) the distance 
between the lines ab and cd. 
Length of tibia and tarsus: the distance between the dorsal limits ; 
best obtained from the anterior surface or edge. 
Second and third antennal segments: in making these measurements 
care should be used that their full length is obtained. 
Sections III and V ofcosta: the length is measured along the shortest 
line connecting the ends of the veins in question (PI. 4, fig. 24). 
Geographical Distribution. 
Species of Sarcophaga have been described from all the life zones. 
The genus is therefore cosmopolitan and it may be that certain of its 
species are as well. Sarcophaga haemorrhoidalis Meigen, S. dalmatina 
Schiner, and S. falculata Pandelle have been reported from North 
America, Europe, Africa, and Asia. S. tuberosa Pandelle as repre- 
sented by its various subspecies harpax (Pandelle), exuberans (Pan- 
delle), and sarraceniae (Riley), has a like distribution. The wide 
distribution of the species of these two groups is not easily accounted 
for. Whether their present distribution may have been brought about 
by natural migration or whether artificial means have been concerned, 
it is impossible to hazard even a suggestion. It is, however, worth 
while to draw attention to the fact that so far as reported occurrences 
make it possible to say, it is only these two groups, each consisting of 
remarkably closely related forms that have so extended a range. 
