Mr. R. B. Sharpe’s Catalogue of Accipitres. 467 
adult dress of B. retnwardti which are pointed out by Mr. 
Sharpe in his Catalogue, one leading feature is that the lower 
breast and abdomen are, in the young bird, “ barred with 
blackish more narrowly than in the adult ;” the widening 
of these dark bars, and their assumption of the slaty-grey 
tint, which seems to be their final colouring, is, apparently 
accomplished very gradually, and a similar gradual course of 
change probably characterizes the variations observable in the 
barring of the tail. 
Mr. Sharpe, in his valuable paper on Dr. Meyer’s collec- 
ticns of birds, published in the ‘ Mittheilungen des k. zool. 
Museums zu Dresden’ for 1878, says, under the head of 
Baza reinwardti, “the young bird is distinguished not only 
by its browner plumage, but by its tail, which is brown, with 
five dark brown bars, whereas in the old bird the tail is 
grey, with two basal bars and one broad terminal* bar of 
black.” 
This, as a general statement, is quite correct, but some 
variation in the number and character of the caudal bars 
occasionally occurs. One young bird in the Norwich Mu- 
seum has five such bars as described by Mr. Sharpe; two other 
immature, but more advanced specimens, in the same collec- 
tion, have only four dark bars; in one of these examples the 
entire adult plumage has been attained, with the exception 
of the tail, all the feathers of which are still those of the 
immature dress. A fourth specimen, killed whilst moulting, 
only retains two immature brown rectrices, both of which are 
lateral and bear six dark-brown transverse bars; and it is 
remarkable that a new lateral grey feather also bears six bars, 
but of a slaty-black hue on a grey ground; the central rec- 
trices are also new and similarly coloured, the bands upon 
them bemg two in number, besides the subterminal one. 
These four specimens are all from North-western New 
Guinea. 
In one of the specimens in the Norwich Museum, said to 
be from Borneo, but probably incorrectly, there is but one 
* This bar, perhaps, ought rather to be termed “ subterminal,” as it is 
usually succeeded by a slight pale tip to the rectrices. 
212 
