STORM PETREL. 169 
322. FORK-TAILED PETREL—(Tihalassidroma Leachit). 
Subject to the same remark as the two last. 
323. STORM PETREL—(Thalassidroma procellaria). 
Mother Carey’s Chicken.—This is said to be the smallest web- 
footed bird known, and it is the last as well as the least. It never 
comes to the shore except at the breeding-season, and-only seeks 
comparative shelter under the pressure of very heavy weather, 
It breeds in the Scilly Islands, some of the islands on the Ivish 
coast, and abundantly on St. Kilda, the Orkneys and Shetland. 
They breed in holes in a cliff, or under large-sized stones, which, 
from their great size and the accumulation of boulders and large 
shingle about them, afford many deep recesses well suited to the 
wants of the nesting Petrel. Like the Manx Shearwater, they 
are by no means silent in their nest-holes, but make themselves 
distinctly audible to the passenger above. They lay one white 
ege, a little exceeding 1 inch long, by 2 broad. 
