PELECANIFOEMES. 
instead of ignoring them he might have been able to indicate the subspecies, 
but such things did not exist according to his ideas and consequently did not 
exist in nature. 
The fourth genus, He7nisula, stands quite alone in its coloration, being, 
instead of the usual white, dark sooty-brown above, with the neck and chest 
also of that colour, the breast and under-parts only being white. In a group 
where the fixity of coloration is proven to be a very ancient item, such vivid 
alteration would alone caU for generic recognition. The birds are, however, 
small Gannets with comparatively shorter tail as compared with the other 
Gannets, and fourteen tail-feathers, the same as in those. 
It is a tropical genus, practically coincident with the other small white 
Gannet but apparently with very different habits. Phylogenetically this 
appears to be the nearest relation, but a great deal of difference now exists. 
No subspecies were recognised, as usual, by Ogilvie-Grant, but that does not 
mean that such were non-existent, nor easily recognisable. 
The Family Fregatidce has only one genus, Fregata, which ranges 
throughout the Tropics in all oceans. Four species are now known, though 
only two were on record when I begun my investigations. These are fuUy 
dealt with later, so can be shortly dismissed here, but their distribution and 
plumage changes call for comment and much study and I hope my 
contribution will induce other and probably better situated workers to 
take an interest in this group. 
The Family Phcethontidce is represented by the single genus Phoethon 
in the Catalogue of the Birds of the British Museum, in the same manner as 
the Brissonian Fula was employed. The half dozen species there recognised 
represent, in my opinion, different generic types, and the two species which 
come into the Australian Avifauna do not come into the restricted genus 
Phceihon. 
The genus SccBO'phcethon covers large Tropic Birds of white coloration 
with long tail of sixteen feathers, the two middle ones being imnjiensely 
elongated ; the young are beautifully mottled black and white. 
The members of the genus Leptophcethon are small Tropic Birds of 
uniform coloration — white in two species, a beautiful orange in the third, with 
comparatively a longer tail of only twelve feathers : the young are mottled 
black and white as in the preceding genus. 
The members of both these genera range throughout the Tropics of all 
the oceans. 
The genus PhcEthon as restricted covers species which never take on the 
beautiful white coloration but retain in the adult the barred plumage 
observed in the juvenile of the preceding genera. While the tail is very long. 
159 
