296 ROBERTS, Birds of the Granite Belt ITs'a??]" 



analogous meaning having a similar function. The dome of .llbo- 

 (jnlaris and of Lineata are, it will be seen, even on reference to 

 the plates, analogous to the side of Brcvirostris and to the front 

 of Pusilla. In the case of the two former the nest is a true 

 hanging nest, and its mode of attachment is by producing the 

 sides uj)wards, enclosing in this sweep the dome, which becomes 

 rudimentary, whereas in Brcvirostris the sides are not produced 

 upwards, and the dome is fully de\eloped and exposed U) view. 

 Pusilla is most interesting, and there is evidence that the nest is 

 transitional. In one illustrated, and this is typical of the nest 

 built in a fairly open bush, there is distinctly one point of sus- 

 pension, but in the other (an assurance is given that it is abso- 

 lutely accurate and made without exaggeration, a photo, being 

 useless on account of lack of detail), in which there are appar- 

 ently several points where weaving into the supports has taken 

 place, it will be noted that these points are all derivates of the 

 front, which is apparently "slipped" upwards and as well slightly 

 overlapped the sides. So it will be seen that the "dome" in the 

 ordinarily acce])ted term of the word, of Lineata and .llbogularis 

 are homologous; they are not homologues of the dome of Pusilla, 

 and none are homologues of the dome of Smicrornis. In Regit- 

 loides the dome is apparently a true dome, in that it is a derivative 

 of the top of the nest. In Sagittata's case the dome is, as in the 

 case of the Malurns group, a derivative of the back of the nest. 



For the sake of more accuracy we would suggest, therefore, 

 in scientific descriptions, that some prefix should be given to 

 ""domed" indicating its origin. The true domed nest of Regidoides 

 might be termed domed, Lineata lateral-domed, Pusilla anterior- 

 domed, Sagittata posterior-domed, and Brevirostris domed but 

 laterally suspended. It is not wished to labour any points, but 

 the difficulty in the matter of the anterior-domed group we are 

 the first to admit ; these with us are all built by Pusilla, and 

 present a certain amount of divergence and variation which war- 

 rants some elaboration. We would define as anterior-domed 

 those nests which are suspended above from one or more i)oints 

 situated higher than the nesting chamber and in which the sus- 

 pension points converge to form a lower lip to the opening of 

 the nest, thus forming an anterior sling for the nest. 



Now, what emerges from all this? Simply, apart from ipso 

 facto, that it may be the key in certain cases as to what are 

 species and what are sub-species: as an instance take, .say, the 

 points in dispute in regard to the .Icantliizae (Mathews v. 

 R.A.O.U. Check-list). All the species agreed upon by both build 

 nests which should each be recognisable by an expert : those in 

 dispute are lumjied by Mathews under rusilla, which pre- 

 supposes that their nests are similar to an extent ec|ual to the 

 similarity in the birds themselves; if this supposition is correct 

 an impartial judge would award the case to him; if the nests do 

 not conform to the derivation of the anterior-domed nest given 



