24 EINAR LONNBERG 
may according to modern views be reason enough to distinguish the Petrels 
from Easter Island as a subspecies. This appears the more suitable as the 
latter by its difference from /era/dica approaches the south atlantic armn- 
joniana from the Trinidad Island. This is f. i. the case with the pattern of 
the feet with the outer toe black, and with the comparative darkness of the 
under tail-coverts. 
The Petrel from Easter Island differs on the other hand from armznjoniana 
by the white on its forehead, lores and sides of head &ca. 
Probably all these three Petrels are most correctly to be regarded as geo- 
graphical subspecies of one and the same species. 
According to Mr. BACKSTROM the soil of the islet Motu Nui was so hard 
that this bird could not make any burrows but had the eggs directly on the 
open ground among the grass, without any nest. 
The young of this Petrel io slate grey all over its fluffy downy coat. Some 
eggs were also seen, but they were much incubated and ready to hatch. 
In his works »The Birds of Australia», Vol. 3, p. 152, MATHEWS has 
expressed the opinion that SOLANDER’'s specific name agz/zs should probably 
be applicable to a Petrel breeding on Easter Island. This may be true, but it 
cannot be applied to the species described above, as SOLANDER states that 
the crissum of his agz/7s together with other lower parts is white and then 
again says: »Cauda... subtus quoad maximam partem pennis longis crissi albi 
tectis». He also says: »Ala..., subtus in medio alba e tectricibus totis niveis... 
angulo humerali niveo», which does not suit this bird. 
Sula cyanops Sunder 
Native name: Luru. 
Motu Nui: 1 ¢ immature, 7°/¢ 1917. 


