Key to the Species. 
A. Under-surface white; upper-surface dark. 
a'. Larger ; wing over 300 mm. ; head streaked P. leucomelas, p. 48. 
¥. Smaller ; wing under 230 mm. ; head not 
streaked. 
a". Wing over 210 mm. ; upper-surface 
blackish-brown. 
a'". Larger; dark colour encroaching on 
neck . . . . . . P. reinholdi-huttoni, p. 77. 
h'". Smaller ; neck white . . P. reinholdi reinholdi, p. 74. 
h". Wing under 210 mm. ; upper-surface 
brownish- black . . . . . . P. Iherminieri nugax, p. 72. 
c". Wing under 210 mm. ; upper-surface 
bluish-black. 
c'". Larger and darker . . . . P. assimilis assimilis, p. 50. 
d'". Smaller and lighter . . P. assimilis tunneyi, p. 71. 
B. Under-surface dark, like upper-surface, 
c'. Tail long ; wedge shaped. 
d". Lighter . . . . . . P. pacificus chlororhynchus, p. 78. 
e". Darker . . . . . . . . P. pacificus royanus, p. 85. 
d'. Tail short ; rounded 
f. Bill stout, light coloured . . . . P. cameipes carneipes, p. 89. 
Bill slender, dark coloured. 
e'". Bill long ; wing about 300 mm. P. griseus griseus, p. 92. 
/"'. Bill short ; wing about 280 mm. 
a"". Under wing-coverts uniform 
with breast . . P. tenuirostris hrevicaudus, p, 99. 
h"". Under wing-coverts light, form- 
ing a contrast P. tenuirostris intermedins^ p. 104. 
47 
