oe 
1893. ] Flowers and Insects. 53 
time when it blossoms (May) only the females of Bomébus are 
flying. The disks are applied to the bee’s clypeus, which in 
the female is bare. The clypeus of the male is so hairy that 
the disks could hardly be properly fastened to them. Long- 
tongued species of Anthophora and Synhalonia are flying 
while the flowers bloom and can reach the nectar, but I do 
not believe the flowers are adapted to them, because the 
males, which fly at the same time, have hairy faces, and they 
would be as apt to visit the flowers. When the pollinia are 
withdrawn by a bee they standin a nearly horizontal position, 
since the bee’s clypeus hasits face directed nearly vertically, so 
that in moving downwards to a position in which they will 
strike the stigma they must be assisted by their own weight. 
On May 13th I found a patch of five plants, which bore 
twenty flowers. With the exception of three flowers, the 
pollinia were removed from all, and most of the stigmas had 
received pollen. I saw the flowers visited by the females of 
Bombus separatus Cr. and B. americanorum F. The probos- 
cis of the former can drain the short-spurred flowers and ob- 
tain some of the nectar which rises in the long spurs. Bom- 
bus americanorum can easily exhaust the longest spurs. A 
specimen of this bee which I captured at the flowers has a 
pair of pollinia on the clypeus. 
HABENARIA LEUCOPHAA Gray.—The plant is rare. It 
§tows on prairies. The stem rises from 4 to 8 and bears a 
raceme of greenish white flowers. The flower measures about 
20™ long by 15™™ wide. 
he upper sepal and two upper petals form a galea which 
shelters the anther. The labellum is three parted, each di- 
vision being fimbriate. The disks are set one on each side of 
the entrance to the spur and are separated about 2™, so that 
when the hawk-moth throws its proboscis to one side or the 
other, it is apt to remove one of the pollinia, but is not likely 
to extract both of them. The spur is very slender and meas- 
ures from 35 to 40™ in length, indicating that the flower is 
adapted to Sphingidae. The nectar does not seem to be en- 
closed between the walls of the spur but appears to occupy 
the cavity. The height to which it rises can be seen from 
pres outside. Sometimes it fills the spur for 10°" above the 
ip. 
I have found the plant in bloom from June 12th to July 
l2th. July 2nd I captured at the flowers a specimen of Chaero- 
