INTRODUCTORY NOTE 
T he notes I have added to Colonel Swinhoe’s paper are derived from the 
observations of Mr. Robinson and myself in the Patani States and 
Perak, Mr. Robinson being solely responsible for those specimens 
collected in Selangor.^ 
Our collections must not be regarded as in any way exhaustive ; it rather 
illustrates the variety of the Heterocera in the districts visited, seeing that 
the two hundred and sixty-nine species enumerated are, in very many 
cases, each represented by a single specimen or by two, while not unfre- 
quently a genus, or even a family, is included on the same basis, indeed, 
there are two hundred genera noted and barely six hundred specimens. The 
specimens were collected casually, as they came, and with scarcely any process of 
selection. This consideration I have thought it well to put forward pro- 
minently, as it is of importance in the study of certain biological phenomena. 
It will be readily seen that a very large proportion of the collection 
was made round our lamp at night ; and that most of the specimens so 
secured were taken on a comparatively small number of evenings. These 
evenings were usually showery, with bright (often moon-lit) intervals, with 
sudden gusts of wind and calm periods, but we could never be sure that 
many moths would be attracted on such a night, and on several occasions 
large numbers were attracted under wholly different atmospheric conditions. 
It is probable that shelter from the weather was often as important a source 
of attraction as the light, and that many of the moths were actually impelled 
to us by the wind. 
The series of the different species obtained are far too small to permit 
wide generalizations as to the distribution of the Heterocera in the Malay 
Peninsula, but one thing they seem to indicate — that there is no such absolute 
separation in this group between the fauna of jungle country in the plains 
and that of the high mountains, as there is, say, in the case of the birds. 
NELSON ANNANDALE 
I. The Selangor specimens were, with very few exceptions, collected during a few moonlight nights in May, in 
a bungalow at the summit of the Semangho Pass (2,700 feet), on the borders of Selangor and Pahang. H.C.R. 
