June 21 At 11 AM went to the rock piles where some witch studied petrels. He had several nest sites marked, all in rock piles. I looked in many of these spots and found a large proportion of the marked sites occupied with ashy petrels. Two had bands (may have been others too) which probably indicates that the petrels return to nest in the same burrows from year to year. All the observed birds except one were incubating single eggs, which were beige color, all the same, and very rounded at both ends. The birds showed fright when I pecked in the crevices and cropt into the furthermost crevices. Two young Cassin auklets were found during this trip. Both were adult size and had adult feathers, but also had the remains of fluffy down on the back and breast. The east side of S. Farallon Is. seems to be an especially suitable place for auklet burrows because the ground is covered with the holes.