CHATHAM ISLAND PETREL. 
The maximum bill length in axillaris hardly attains the minimum measure¬ 
ments in a long series of typical cookii. 
Oliver says it differs from cookii in the colour of its feet, which are pinkish, 
feet flesh colour, the terminal portion of the webs and toes black. 
Breeds in Chatham Island. 
Breeding habits .—-Archey and Lindsay state, on the authority of H. G. Blyth, 
that this species breeds in deep tunnels among the roots of trees on the cliffs of 
the south-west portion of the main island, near the two sharp volcanic cones 
known as the Homs. 
The nesting habits and eggs of all cookii and its allies are presumed to be the 
same. 
No. 112. 
COOKILARIA COOKII. 
(PYCROFTI.) 
BLUE-FOOTED PETREL. 
Pterodroma pycrofti Falla, Rec. Auck. Inst. Mus., Vol. I., No. 4, p. 176, Sept. 25th, 1933. 
Taranga (Hen) Island. North of the North Island of New Zealand. 
Type, adult male. Similar to cookii , but with a much shorter bill, shorter wing and darker coloration 
of the upper parts. 
Adult female resembles the adult in plumage and is not appreciably different in size. 
Breeding. Taranga Island, presumably at the end of January. 
The measurements of a mated pair are : wing 215 and 217 ; tail 88 and 86; 
tarsus 28 and 27 ; middle toe 33.5 and 34.5 ; culmen 23.5 and 23. 
Typical cookii measured by the same worker, give: wing 230-240 ; tail 
88-95; tarsus 27.5-30 ; middle toe 36-39 ; culmen 25.5-28.5. And of leucoptera : 
wing 221-233 ; tail 92-94 ; tarsus 28-29 ; middle toe 37-38 ; culmen 25-26.5. 
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