110 The Birds of Pembrokeshire. 
last day of May we visited this wall, but as the Storm-Petrels are 
late in breeding there were no eggs there then, although we 
distinctly perceived the unmistakable Petrel odour clinging in 
places to the stones, showing that the birds were at that time 
visiting the wall. The Storm Petrel does not lay its single white 
egg before the end of June, or even later, for in the Zoologist 
for 1886, p. 457, the Rev. H. A. Macpherson mentions an 
adult and nestling that he saw in Leadenhall market, in London, 
as late as 2oth September. Both, he was told, had come from 
Skomer; the nestling was taken on 18th September, and was 
fully feathered, but still retained some of the sooty down, especi- 
ally upon the belly. After severe gales the little Storm Petrel 
is occasionally picked up inland at some distance from the coast. 
In stormy weather in the autumn some are captured at the Light 
House on the South Bishop’s Rock; on the night of October 
14, 1883, eight were taken; it was misty weather, with a S.E. 
breeze, and a drizzling rain. A great number of small birds 
struck that night against the light, ninety were killed, and two 
hundred were taken in a net. Three ‘ Falcon Hawks and a 
Large-horned Owl” were also present, and “made sad havoc 
among them” (Migration Reports, 1883). It seems strange that 
the Storm-Petrels should be betrayed into danger by the glare 
of the Light House lights. One would have thought that, from 
being always about and skimming over the water at night time, 
they would have become accustomed to the lights ; we can only 
suppose that in misty weather they are bewildered and become 
reckless, and so approach too near to what in ordinary weather 
they would be careful to avoid. 
LEACH’S PETREL, Procel/aria leucorrhoa.—This is a little larger 
than the Storm-Petrel, is of a browner black, has a grey line 
across the edges of the wing-coverts, and a deeply forked tail, 
so that one of its common names is the Fork-tailed Petrel. It 
is not known to breed on any of our islands, but it is not very 
rare, as a visitor in stormy weather, and, like the Storm-Petrel, 
is occasionally picked up inland. The Rev. Clennell Wilkin- 
