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 heraldica approaches the south atlantic armin- 

 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 arminjoniana 

 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 agilis 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 agilis 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: i $ immature, ^^/e 1917. 



