SOME OF THE OUTLIERS AMONG BIRDS. 



773 



The first to be noticed is that singular bird known as the ham- 

 merhead, a heronlike form about as big as an average-sized bit- 

 tern, which derives its name from the fancied resemblance of its 

 head to a hammer. This only holds true, however, when its other- 

 wise erectile crest is lowered so as to be in a line with its beak (see 

 Fig. 7). It has been known to science since 1760, when Brisson 

 described it, it being the Scopus umhretta of ornithology, and 

 ranges over the greater part of the African continent. In plum- 

 age it is of a dingy brown with purplish reflections, while a 

 series of blackish bars mark its tail across. Inactive by day, it is 

 lively enough as night approaches, at which latter time, it is said, 

 it gives itself up to a behavior of a very remarkable order. Ac- 

 cording to Sharpe, its nest is " a structure of great bulk, with 

 chambers inside, built of branches and twigs and five or six feet 

 in diameter, capable of bearing the weight of a man." This nest 

 has a roof to it and is carefully lined with clay, the entrance being 



Fig. 7. The Hammerhead (iScopus vmhref.fa), with a Pair of Shoebills in the Distance 



{. rex). 



at the side. Scopus is known to lay white eggs, but up to the 

 present writing the nestling has not been described. Recently 

 the bird has been found in the island of Madagascar. 



One other remarkable African outlier is the famous Balceni- 

 ceps rex, known to English travelers as the " shoebill," a stork- 

 like heron, A pair of these birds is shown in the distance in 

 Fig. 7 of the present article, and the whole of this figure, exe- 



