Mr. T. Ayres on the Ornithology of Transvaal. 295 



Potchefstroom, was referable to the northern A. minuta ; 

 but having recently reexamined this specimen, and compared it 

 with numerous examples both of A. minuta and of A. podiceps, 

 I am disposed now to refer it to the latter species, and to 

 believe that A. minuta has not been satisfactorily identified 

 as a native of South Africa. The two species (or rather sub- 

 species) are, in fact, very closely allied, and, when in imma- 

 ture plumage and not sexed, cannot always, as it seems to 

 me, be discriminated with certainty. 



It may perhaps be useful to record the following memoranda 

 which I have noted with reference to these two races of Little 

 Bitterns : — The adult males of A. podiceps have the sides of 

 the head and also the sides and back of the neck of a vinous 

 brown, with more or less of a rufous tinge, whilst the corre- 

 sponding parts in the adult males of A. minuta are of a 

 somewhat pale fawn-colour, which is occasionally suffused 

 with a very slight tinge of grey. The adult females of both 

 species have the sides and back of the neck of a rufous 

 brown, but the rufous tint is decidedly deeper and richer in 

 the iemales of A. podicejjs than in those of A. minuta, and 

 both in the females and immature birds there is a general 

 tendency in the southern race to exhibit a slightly deeper 

 tint on the brown portions of the plumage than is usual in 

 the more northern species. Except as above mentioned, I 

 do not find that the two races differ in coloration ; but the 

 average dimensions of specimens of A. minuta are slightly 

 larger than those of A. podiceps, the measurements of male 

 birds of both species being usually a little in excess of those 

 of the females, which makes it needful to compare individuals 

 of the same sex in discriminating the two races. 



The following measurements (in inches and decimals) have 

 been taken from specimens in the collections of my son, Mr. 

 J. H. Gurney, Jun., and myself, and from others kindly lent 

 me by Canon Tristram, Mr. Dresser, and Mr. Seebohm; the 

 examples of A. podiceps are all from Transvaal, except one 

 adult male in my collection from the Gaboon, which is the 

 most northern example of the southern race with which I am 

 acquainted. 



