42 



examined a great many specimens, he had never yet met with the porch-like 

 contrivance, and in an ai'ticle recently contributed to the Ihis (July, 1870, 

 p. 393), he remarks, — "^'I have never seen the poi'ch described by Mr. 

 Buller in his Essay." 



Mr. Potts, in his intei-esting paper on the nests and eggs of New Zealand 

 birds {Trans. N.Z. Inst., 1869, p. 50), sta,tes that this species Tisually lays six 

 eggs ; but, so far as my experience goes, four is the normal number, although 

 there are sometimes more. They differ somewhat in size, and vary in shape 

 from the true ovoiconical to a slightly pyriform type. They are sometimes 

 piire white, but more generally freckled with pale red, and ai'e so fragile in 

 textui^e as to bear only the most delicate handling. Mr. Potts accounts for the 

 occurrence of white eggs on the supposition that they ai'e the product of 

 young birds ; but I am more disjDOsed to consider this, taken in connection 

 with the slight difference in form and size, as further indicative of the exist- 

 ence of two distinct species. 



Among the substances used as building materials by this bird, spiders' 

 nests are always conspicuous ; indeed, in some specimens the whole exterior 

 surface is covered with them. The particular web chosen for this pvirpose is 

 an adhesive cocoon of loose texture and of a dull green colour. These 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 requisite building material, it finds also a 

 plentiful supply of food — an economy of time and labour 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. 



9. Petroica Dieffenbachii, Gray. 



In characterizing the above species iyoy. Ereh. and Terr., Birds, p. 6), 

 Mr. Gray states that it is " veiy like Petroica onacrocephala, but is altogether 

 smaller in size, and with the small and narrow bill of P. toitoi." 



Petroica toitoi is confined in its range to the North Island, where it is 

 very common. It may readily be distinguished from the other species by the 

 pure whiteness of its under parts. The South Island is the habitat of 

 P. ^macrocepliala, and Auckland Island is incbided in its range on the authority 

 of Mr. G. P. Gray. I obtained specimens at the Chatham Islands during a 

 visit there in 1855, but I have failed to detect any such difference in examples 

 from that locality as would justify the recognition of a distinct species, as 

 proposed by Mr. Gray. I think it will be found necessary to expunge 

 Petroica Dieffenbachii from the list of species, for I do not believe that it has 

 any real existence. 



