Mr. T, Ayres on the Ornithology of Transvaal. 289 
sects which frequent the honey-dews on the pollard willows, 
for weeks together, appear to attract it. It is very retiring, 
and difficult to see amongst the dense foliage, where it sits 
and babbles for hours together. The hen bird has a short 
harsh note of alarm. 
[Some remarks of Mr. Ayres in ‘^The Ibis'’ for 1865, 
p. 266, which were intended to apply to this species, have 
been erroneously referred by Captain Shelley in ^ The Ibis ^ 
for 1875, p. 72, and by Mr. Sharpe in the second edition of 
Layard^s ^ Birds of South Africa,^ p. 292, to A. palustris. 
Mr. Seebohm has called my attention to the fact that this 
species comes exceedingly close to A. dumetorum, a native of 
Eastern Europe and of some parts of Asia, and has kindly 
furnished me with the following remarks on this subject:— 
At the first glance, Acrocephalus hceticatus seems to be 
the same bird as A. dumetorum ; both are about the same 
size, the relative lengths of the wing*primaries are the same, 
and there is no diflerence in the respective lengths of the 
bastard primary or of the culmen. It is true that the colour 
of the upper part of A. bmticatus is more of a coffee-brown, 
whilst in A. dumetorum the colour is more of an olive-brown; 
' but that is exactly what we might reasonably expect to be the 
difference between summer and winter plumage. 
The argument from the known facts of geographical distri¬ 
bution is all on the side of the identity of the two species. All 
the dated skins of haeticatus which I have seen were obtained 
in South Africa between October and April. A. dumetorum is 
found in Eussia, from St. Petersburg to the Ural, from June 
to September; it also breeds in North Turkestan, in Siberia, 
and in the Himalayas, and it winters in fhe plains of India. 
I am inclined, however, to admit the distinctness of the 
two species. A careful examination and comparison of seven¬ 
teen skins of A. bceticatus and twenty skins of A. dumetorum 
leads to the following results :—The colour of the upper parts 
of A. bceticatus is decidedly more of a coffee-brown than is the 
case with the skins of A, dumetorum in summer plumage, and 
perceptibly more so than is the case with the skins of the 
latter bird in winter plumage; in fact the difference in colour 
SER. IV.-VOL. II. x 
