564 Mr. Harold Powell on the 
Tlesperia sao ovipositing freely on the flower heads of 
Poterium, but, although I watched three $2 of H. sidae 
for as long as it was possible to keep them in sight, 
they made no attempt to lay eggs. They were probably 
too fresh and had perhaps not mated. 
Their flight is very rapid and erratic, and they were 
easily lost sight of. One may be seen coming up the 
path between the narrow strips of prairie, in its rapid, 
jerky way, and it may perhaps settle, but when approached 
it is off again with a whirr of wings distinctly heard, and 
is quickly lost in one of its long zigzags. If one stays in 
the same place it will very probably be seen returning after 
a while, for sixdae does not wander far from its “run.” 
However, if I did not see the skipper in the act of 
egg-laying on that day, I got as far as the fact that it 
only flew where the Potentilla hirta grew, and that 
plant, as I have already said, was local, though it grew 
abundantly enough in patches. I found only two or 
three plants in flower, though it was evident that in a 
day or two it would be flowering generally. 
I did not return to the valley until May 14. In the 
meantime the weather had been mostly fine and warm, 
but the 10th, 12th, and 13th were wet. The Potentilla 
was then flowering well, and there were as many sidae 
about as on the previous occasion. I again took two 
freshly emerged specimens, but most showed signs of 
wear. I recognised a crippled specimen which I had 
seen on May 5. Although the yellow bands of the 
hindwings beneath had faded, its fringes and general 
appearance above were still good. 
Soon after reaching the ground, I saw a 2 seemingly 
feeding on a Potentilla flower, but she went off at once 
across the stream. I kept her in sight, and she soon 
returned to the Potentilla patch, settling on a flower 
on which I supposed she meant to feed, but I saw her, 
with wings still open, curve her abdomen until the 
extremity touched the flower. She kept it there for 
a few seconds and then flew off again. Picking the 
flower, I found an egg amongst the stigmata, nearly in 
the centre. I saw another egg laid in the same way, 
and then I lost sight of the 9. Having got so far, the 
rest was easy. I set to work to examine the flowers, 
and soon found a number of eggs, On three occasions 
I found two eggs on one flower, but the usual habit 
