146 BIRDS OF THE 
from November 1898 to March 1899, made collections of 
birds on the Upper Kapoeas ') and on the River Mahakkam 
(Hast-Borneo) and its tributaries. 
Moreover I am indebted to Mr. L. Westenenk, an officer 
in the Dutch colonial civil service, at that time » Assistent 
Resident’”’ at Sanggau, for a small collection of birds 
preserved in spirits, from the junction of the Sekajam 
with the Kapoeas River and sent to me after my return 
to Leyden. 
In my above-mentioned introduction *) I have plainly 
sketched the oro- and hydrographical conditions of the 
country as well as its climate and vegetation, factors which 
are of great influence upon the ornis of the explored ter- 
ritory, so that I hardly need to add any more particulars to it. 
At the same place I called attention to the lack of 
water-birds in my collection, due to my neglecting to spend 
some time in the coast-region, and the small! collection 
made by Mr. Moret at Pontianak has not added an impor- 
ant number of species of water-birds. 
The bird-collections made by Dr. Nieuwenhuis, also 
enumerated in the present paper *), contain among the 815 
1) The letters oe” in Dutch geographical names ought to be pronounced 
as uh”. 
2) Since the publication of this introduction, in which I enumerated (p. 1) 
the publications on various parts of the zoological collections of our expedi- 
tion, the following papers on this subject have been published in the Notes 
from the Leyden Museum: 
M. M. Schepman, description of a new Unio from Borneo. Vol. XX, p. 
92 (pl. 1). 
Dr. O. Finsch, on the specific distinction of the Ground-Cuckoos of Borneo 
and Sumatra. Vol. XX, pp. 983—96. 
Dr. F. A. Jentink, the Mammals, collected by Dr. Nieuwenhuis on his 
second expedition to Borneo. Vol. XX, pp. 113—125 (pl. 2). 
Dr. J. G. de Man, Crustaceans of the Dutch Borneo-Expedition, part I. 
Macroura. Vol. XX, pp. 187—16Y (plates 6, 7 and 8); — id., part [1. 
Brachyura, Vol. XXI, pp. 58--144 (plates 5—12). 
Dr. R. Horst, on the variability of characters in Perichaetidae. Vol. XX, 
p. 206. 
8) These important collections, as well as mine, have kindly ‘been presented 
to the Leyden Museum by the »Maatschappij ter bevordering van het natuur- 
kundig onderzoek der Nederlandsche Kolonién.” 
Notes from the Iueyden Museum, Vol. XXL 
