Order PROOELLARIIFORMES. 
Family THALASSIDROMIDJE. 
No. 114. 
CYMOCHOREA LEUCORHOA. 
LEACH'S FORK-TAIL PETREL. 
1817. Procellaria leucorhoa Vieillot, Nouv. Diet. Hist. Nat., Yol. XXV., 1817-Dec. 26th, 1818, 
p. 422. Maritime parts of Picardy. 
Oceanodroma leucorhoa Salvin, Cat. Birds Brit. Mus., Vol. XXV., p. 348, 1S96 ; Godman, Monogr. 
Petrels, pt. i., p. 8, pi. 4, Dec., 1907. Falla, Rec. Auck. Mus., Vol. I., No. 4, p. 173, 
Sept. 25th, 1933. 
Oceanodroma [Cymochorea] leucorhoa and its subspecies, Oberholser, Proc. U.S. Nat. Mus., Vol. LIV., 
pp. 165-72, Oct. 19th, 1917 ; Mathews, Nov. Zool., Vol. XXXIX., p. 189, Dec. 7th, 1934. 
Oceanodroma kcedingi Anthony, Auk, Vol. XV., Jan., 1898, p. 37 ; near Gaudalupe Island, 
California. 
Oceanodroma l&ucorhoa kcedingi (of Antony) Falla, Rec. Auck. Mus., Vol. I., No. 4, p. 173, Sept. 25th, 
1933. New Zealand. 
Adult male. General colour of the upper surface sooty black ; fore-head from level with the eyes 
to the bill, brown ; rump and upper tail-coverts white, the longest with black tips, and the 
shafts dark ; central tail-coverts sooty-brown with w r hite on the base of the inner web ; tail 
feathers black, the outer web of the outer tail feather white only at the base, like the inner 
web ; the shafts brownish to white at the base ; primaries and their coverts black, like the 
lesser coverts ; the median wing-coverts brown with lighter edges ; under surface brownish, 
including the under wing-coverts and axillaries. Bill, feet, legs and eyes black. Wing 
158 mm.; tail, outer 80, central 63 ; culmen 15 ; tarsus 26 ; middle toe and claw 26. Col¬ 
lected on Muriwai Beach, New Zealand, August, 1922. Wing formulae 2-3-1-4 ; middle 
claw 7 mm. ; outer toe without claw (claw 4 mm.) a trifle longer than middle toe without 
claw ; inner toe and claw equal to outer toe without claw. Kindly sent to me by Mr. Falla 
for description for this work. 
The sexes are alike. 
Nest. Placed at the end of a burrow. 
Eggs. Clutch one ; white, sometimes marked with a few scattered reddish specks : 29 to 31.5 by 
21.5 to 24 mm. 
Breeding-season. June and July. 
The bird is only an accidental visitor of New Zealand. 
From The Practical Handbook of British Birds . 
91 
