270 BRITISH BIRDS' EGGS. 



from the light/' Mr. Yarrell adds, " The egg (and they 

 lay but one) measures one inch and seven -eighths in length 

 by one inch and three-eighths in breadth, rather smaller 

 at one end than at the other, and pure white/' The species 

 is reported to belong to the southern and tropical regions 

 of the globe, though individuals have sometimes been found 

 far north. 



BULWER'S STORM PETREL. Thalassidroma Bulwerii. 

 All the known species of the genus Thalassidroma are small, 

 maritime in habits, and possess an extraordinary develop- 

 ment of wing. With the particulars relating to the nidifi- 

 cation of this very rare British species, we are unacquainted. 



THE STORM PETREL. Thalassidroma pelagica. Birds 

 of this species breed in the Hebrides, and in the Shet- 

 land and Orkney Islands, though in very dissimilar situa- 

 tions, sometimes making the nests in holes in the cliff a 

 great height above the sea, at other times under loose 

 stones of the beach, and occasionally in rabbit-holes. The 

 following lengthened extract from Mr. Dunn's 'Ornitholo- 

 gist's Guide' to Orkney and Shetland, brings us very clearly 

 acquainted with some of the breeding habits of the species. 

 He writes : "I had now procured specimens of almost all 

 the birds to be found in Shetland, excepting the Stormy 



