124 Transactions. — Zoology. 



spiders' nests contain a cluster of flesh-coloured eggs, or young, and in tearing 

 them off the bird necessarily exposes the contents, which it eagerly devours. 

 Thus, while engaged in collecting the necessary building material, it finds also 

 a plentiful supply of food — an economy of time and labor very necessary to a 

 bird that requires to build a nest fully ten times its own size, and to rear a 

 foster-brood of hungry cuckoos in addition to its own" {I.e., p. 42). 



This statement appearing, I suppose, fanciful to Captain Hutton, he 

 ventured, in the " Critical Notes" appended to his Catalogue of New Zealand 

 Birds (p. 73), to pronounce these spiders' webs nothing but fresh- water Algee ! 

 Captain Hutton afterwards wrote to me, admitting his error, but I cannot 

 find that he has made any avowal of it in his numerous communications to the 

 Institute. This omission is, I think, to be regretted; for while it is perfectly well 

 understood that the " opinions" of a writer on any question of science are a 

 fair subject of criticism and discussion, one naturahst has no right to impugn 

 the accuracy of another in matters of fact, or to throw doubt on his habits of 

 observation, unless in doing so he can adduce something better that mere 

 conjecture. 



Eallus modestus, Button. 



The October number of "The Ibis" contains a communication from 

 Captain Hutton in defence of this species. He combats my judgment in 

 referring his type specimen to Rallus dieffenhachii, juv. (" Birds of New 

 Zealand," p. 180), and enters upon a long argument to prove that not only 

 are they distinct species, but that they belong to different sub-genera. 

 Inasmuch, however, as there is a fatal mistake in Captain Hutton's premises, 

 his conclusions go for nothing. 



" I labour under the difficulty of never having seen the specimen of Eallus 

 dieffenhachii " is the admission with which he starts, and he immediately falls 

 into the error of supposing that it is scarcely distinguishable from Rallus 

 philippensis, " in fact [to quote his own words] so similar are they that it 

 appears to me doiibtful whether E. dieffenhachii should be retained as a 

 distinct species." Starting, therefore, with the assumption that Eallus 

 diffenhachii and E. 2yhilippensis are the same — in which he is entirely wrong — 

 he proceeds to prove that Eallus modestus " belongs to a different sub-genus 

 from Rallus philip>pensis." He gives a figure to show that "the bill of 

 E. modestus is much more slender and longer in proportion to the size of the 

 bird than in E. philippensis" and indicates other points of difference. 



Granting the whole of his argument as regards Eallus 2)hilippensis, that is 

 quite beside the question of Eallus modestus and E. dieffenhachii being the 

 same, which is the only point in issue. 



Let the reader glance at the subjoined figures (by Keulemans) of the heads 



