46 Christmas Island. 



the secondaries black-shafted, the outer primaries with more or 

 less black along the outer web ; tail-feathers white, with a sub- 

 teiTuinal black spot ; a cii'ciilar spot of black in front of the ej'e, 

 extending below backwards in a line under the latter, and with 

 a black line aboye the ear- coverts ; flanks with a tuft of chequered 

 black feathers with white notches and spots. These latter 

 feathers, and also many on the back and secondaries, seem to 

 indicate by the variation of their pattern that the latter changes 

 a great deal, so that the aspect of the feather becomes gradually 

 whiter and whiter. 



['] he most beautiful of the sea birds is the yellow Tropic Bird, 

 which, though much less numerous than Ihe Frigate-birds, is still 

 fairly common. The flight of these birds is swift, though, owing 

 to the rapidity of the strokes of the wing, it often seems as if they 

 were labouring. I never saw them sail except for a short distance 

 when wheeling round. On hot days they may be seen in twos 

 and threes, flying rapidly up and down above and among the tree 

 tops, continually uttering their peculiar crackling cry, and pausing 

 now and then to hover before holes in the trees which seem to 

 offer an eligible position for a nest. It can hardly be said, however, 

 that they make a nest, for the single dark- brown mottled egg 

 is merely placed in a .slight hollow on the floor of a hole in a tree 

 or in the sea cliff. The young bird, when nearly full-grown, is 

 white, barred with black, and since I never saw one in this 

 plumage out of the nest, it seems that the yellow colour is 

 acquired before it flies. The onlj- distinguishing mark of the 

 youngest bird I ever saw flying was the presence of a few black 

 bars on the back just above the root of the tail. Eggs and 

 young were obtained in August and September ; the breeding 

 season seems to be less definite than in the case of the other 

 birds.— C. W. A.] 



Order ACCIPITRIFORMES. 

 21. Astur natalis. (Plate Y.) 



Urospizias natalis. Lister, P.Z.S., 1888, p. 523. 

 Aitur natalis, Sharpe, Handl. B., i, p. 251 (1899). 



(J juv. Flying Fish Cove, August 14, 1897. 



^s'os. 30-33, S 9 juv. Flying Fish Cove, August 13, 1897. 



Iso. 36, 9 ad. Flying Fish Cove, August 2U, 1897. 



^'os. 43-44, 9 ad. j pj .^ j,.gj^ ^ August 22, 1897. 



(J ]UV. \ « o ) » > 



^ juv. Flying Fish Cove, September, 1897. 

 S juv. Flying Fish Cove, October, 1897. 

 9 juv. Phosphate Hill, November 28, 1897. 



No. 3o, S ? ad. I s i^i^.gjjgt^ ^^^^^ August 20, 1897. 

 S ]uv. ) . o . 



