INTRODUCTION. 
In this list three new names are proposed, as follows : Notoplotus, 
Parvifregata , Bruchigavia novcehollandice yorki. 
It may be noted that in the Appendices I have recorded species that are 
visitors or accidental migrants which have only one occurrence at present 
on record. Some of these are of doubtful authenticity, while others are quite 
valid and may be representative of a much larger migration yet unnoticed. 
A peculiar instance is the recent visitation to West Australia of Whitewinged 
Black Terns when they occurred in thousands and yet only a couple of known 
instances had previously been recorded. 
As always emphasised, such Lists as the present are valuable as bases for 
research work and also as keys to the literature, and necessarily are always 
open to rectification in details as more thorough search is made and better 
anatomical investigation takes place. 
All subspecies are grouped upon a binomial species heading, as there can 
be no doubt that Lists prepared in this way will be more useful to the general 
worker. The first-named species is given in heavier type, but this must not 
be taken to indicate that that is the only subspecies I recognise. The 
number of subspecies accepted must always be a variable one, according to 
the material available and to a certain extent upon the personal idiosyncrasy 
of the worker, even if such be quite unprejudiced in the matter. 
There has been some comment on the number of genera I except, but 
compared with the B.O.U. List for 1915, compiled by the “ most conservative 
lumpers on earth,” I find for the same group of ornithology, p. 113 onwards, 
Piciformes to end, that there are 267 species to 146 genera, average 1.82. 
However, four genera between them contain 42 species, leaving 225 species for 
142 genera, average 1.58. Ninety genera are monotypic and thirty have 
only two species to a genus. That is nearly two-thirds are monotypic and 
more than half the remainder have only two species. 
It seems unnecessary to stigmatise as a “ genus splitter ” one who makes 
use of so few more genera than the professed “ genus lumper.” 
GREGORY M. MATHEWS. 
Foulis Court, Fair Oak, Hants. 
23 rd January , 1920. 
IV 
