1869. ] FROM THE SOLOMON ISLANDS. 125 
VII. Heroptongs. 
Distribution. 
Sheet PARED SUETENE Sekpiasecdis leckbadbabe dive baese India, Australia, and Polynesia. 
VIII. Gavia. 
DES SGCENG TUNALE «54. canenlacssatsaeaesanedes Polynesia. 
It thus appears that of the thirty-four authentically determined 
species of birds of the Solomon Islands seventeen are certainly, as 
far as is hitherto known, and three others probably, peculiar to the 
group. Of the remaining fourteen, five have likewise been met with 
in New Ireland, which is one of a neighbouring group of islands 
probably belonging strictly to the same fauna; one has hitherto only 
been found in the Lousiade Islands; and the remainder are of more 
or less extended distribution, being, however, mostly restricted to 
the Papuan Islands. 
But to obtain a better idea of the true nature of the avifauna of 
the Solomon Islands we may first consider very shortly what are 
the principal divisions of the great region of which it forms a part. 
The Australian region (Regio australiana), as I have proposed to 
call this*, appears to be most naturally divisible into five subregions, 
namely :— 
1. The Papuan subregion (Subregio papuana), or Austro-Ma- 
layan Subregion of Wallacet. 
2. The true Australian subregion (Subregio australis), comprising 
continental Australia, with, perhaps, the exception of the northern 
promontory of Cape York, which has been overrun by Papuan forms 
(such as Cuscus, Casuarius, Manucodia, &e.). 
3. The New-Zealandian or Maorian subregion (Subregio mao- 
riana), which is characterized by the recently extinct Dinornithes, 
as well as by the presence of numerous peculiar ornithic types. 
4. The Polynesian subregion (Subregio polynesica), comprising 
the numerous groups of Polynesian islands lying between the Equator 
and the Tropic of Capricorn. 
5. The Sandwich-Island subregion (Subregio sandvicensis), com- 
prising only the Sandwich Islands, which are so very peculiar in 
their zoology that they must, I think, stand by themselves. 
A very short examination of the foregoing list of the birds of the 
Solomon Islands will be sufficient to show us to which of these sub- 
regions this group of islands properly belongs. One of the principal 
features which distinguishes the Papuan subregion from the true 
Australian subregion is the occurrence in the former of numerous 
Indian types which do not extend into the latter. For example, the 
Hornbills (Bucerotide) are entirely foreign to Australia, but are 
found in the Papuan and Moluccan Islands. One species (Buceros 
ruficollis) only has yet been met with in New Guinea. This bird 
also occurs in the present collection from the Solomon Islands. 
Again, the genus Gracula is a well-known Indian form, but extends 
also over the Papuan subregion of Regio australiana, being, however, 
* Journ. Proc. Linn. Soc. Zool. ii. p. 130. 
+ Cf. Wallace, P. Z. S. 1864, p. 273, et Journ. Geogr. Soc. xxxiii. p. 217. 
