204 THE CANADIAN ENTOMOLOGIST 
terminal segment, one a little below the apex." The sketch sup- 
plied by Mr. Johnson indicates that the first of the flagellar seg- 
ments has two of these weak segments, the next two have three 
each while the short terminal segment is not further divided, 
these totalling up to the nine distinct segments in C. primitiva. It 
will be seen from the figures (fig. 3) that the flagellar segments 
in Plerochionea are all short-cylindrical; in C. primitiva (fig. 4) 
the basal segments are short with short verticils, these segments 
gradually becoming more attenuated and provided with longer 
bristles, the last segment shorter with three terminal bristles. 
The male hypopygia of Chionea and Plerochionea show a 
peculiar, powerful type of genitalia, consisting of a massive pleurite 
and a single elongate pleural appendage (figs. 1, 2). In Crypieria 
the appendages are small, two in number and quite normal. Thus 
in the structure of the antenna, Chionea comes closest to Cryp- 
teria, but in the hypopygium the condition is remarkably close to 
Pterochionea. There can be little doubt but that these two genera, 
with perhaps others yet to be discovered, are the direct ancestors 
of our familiar snow-flies, Chionea. As stated in another paper, 
this interpretation will place the group at the very end of the 
eriopterine series. 
Chionea primitiva, sp. n. 
Size large; form stout; entire body hairy; head elongated; 
antenna with nine flagellar segments beyond the fusion segment. 
Male. — Length 5.8 mm.; diameter across thorax, 1.5 mm. 
Mouth parts yellowish brown; palpi dark brown. Antenna 
elongate, the scapal segments yellowish brown, the flagellum 
darker; first segment of the scape a little broader basally, with a 
group of long bristles on the outer face; second segment narrowed, 
basally enlarged, darkened and provided with bristles beyond the 
basal portion; fusion-segment of the flagellum conical, with short 
verticils; it is shorter than the second segment of the scape but 
longer than the following segment of the flagellum; beyond the 
fusion-segment are nine distinct segments, increasing in length 
toward the tip of the organ, the verticils also increasing in length 
from the base outward, those of the first four segments shorter 
than the segments that bear them, the others very long, longer 
than the segments that bear them ; the terminal segment is smaller. 
