Letters, Extracts from Correspondence, Notices, fyc. 117 
“ The geographical boundaries of the two species will be an 
interesting subject of inquiry. 
“ Is it possible that the presence or absence of the nuchal 
collar is not a specific, but a sexual distinction ? 
“ Perhaps this is a question deserving the attention of ob¬ 
servers who may have the opportunity of ascertaining the fact. 
_« J. H. Gurney.” 
Dr. G. Hartlaub has lately received some important ornitho¬ 
logical MSS. from Freiherr von Heuglin, relating to his recent 
discoveries on the White Nile. One of these we have already 
given (anted, p. 31). Dr. Hartlaub further mentions a new 
Corephegnathus, a Lamprocolius, two Ardece, and a Ciconia, as 
being of great interest. The latter is described, “ cauda longa, 
profunde furcata, alba; rectrice prima valde elongata, nigra.” 
This very anomalous Stork von Heuglin calls Ciconia pruysse- 
naeri, after the Belgian Baron Pruyssenaer de Lawostyne, from 
Bruges, who has lately been exploring the White Nile. 
Mr. Gerard Krefft, in a letter dated Sydney, April 24, says :— 
“ During the last week, I have noticed a great number of the 
Yellow-eared Black Cockatoo ( Calyptorhynchus xanthonotus ). 
Flocks of from ten to fifty have been dying over the Museum, 
which is situated in a central part of the city. Their favourite 
place of resort is the thick scrubby country between Bandovick 
and Botany. Though within a few miles of Sydney, this place is 
seldom disturbed by any of our Sunday sportsmen, which may 
account for the tameness of the birds; for I approached within 
twenty yards of a large flock several times. They seem to feed 
on the Banksice and Eucalypti, of which all the thickets are com¬ 
posed; and their plaintive cries may be heard for miles. 
“ If one of these birds is wounded, you are sure of the whole 
flock; they will not leave a companion m distress: and I am sorry 
to say that when on a collecting expedition to the Lower 
Darling, I often took advantage of their attachment to each 
other, and bagged as many out of a flock as the men of the camp 
could skin.” ___ 
The following extracts are from Mr. BlytlPs recent letters:— 
“ We have two allied species of Owl from Africa, each of which 
