446 Larval Habits of Bee-Fiies, [June, 
above. Toward the period of pupation, it becomes more opaque 
and more contracted.! 
Pupa (Pl. v1, Fig. 2)—Average length 8.5 mm. Color honey- 
yellow, but varying with age, the head and thorax assuming a 
dark color with maturity. Head narrow, with two sets of three 
stout, dark spines on the top, all on a common prominence, the 
two lower ones of each set connected at base; a pair of smaller 
frontal spines near the base of proboscis, which is protuberant 
and laid along the breast, extending to near the tips of the wings; 
the face with two parallel depressions running from between the 
triple tubercles ending in two fossz above the frontal spines ; two 
basal, medio-dorsal tubercles. Thorax unarmed, the prothoracic 
each abdominal joint with a circle of hairs, those on lateral ridge 
stoutest and one-third the width of abdomen in length ; eight 
pair of abdominal spiracles (making ten with those on thorax), 
the first and last pairs rather difficult of detection. 
TriopitEs Mus.—The habits of this insect in the larva state are 
precisely like those of the preceding : 
Larva (Pl. v1, Fig. 4).—So greatly resembling that of the Sys 
toechus that it is well nigh impossible to separate the two with 
tcechus in the broader and more bulbous head ; in the two sets of 
three stout spines at top being well separated; in the frontal pair be- 
general form and structure the true Bombylius larva agrees very closely with those 
here described, as we know from Dr. Chapman’s description. 
