THE BIRDS OF AUSTRALIA. 
middle claw ; in the bill in the same stage a rather distinct hooked tip is 
seen and the nc^trils are distinctly shown as linear slits in a broad groove 
between the culmen and lateral edge, while serrations are not yet in evidence 
on the edges of the mandibles. 
The preceding applies wholly to Piscatrix. 
In the Austral Avian Record, Vol. II., pp. 55-6, 1913, I wrote as 
follows : 
“ Parasula, gen. nov. Differs from Sula Brisson in its much larger size 
and different number of tail-feathers : from Morus Vieillot in the different 
number of tail-feathers. Type, Sula dactylatra bedouti Mathews. 
“ Hemisula gen. nov. Differs from Sula Brisson in the number of tail- 
feathers and its proportionately shorter tail. Type, Sula leucogaster rogersi 
Mathews. 
Note. — ^All the Gannets have been lately, and without much reason, 
included in the genus Sula. The differences in size, coloration, structural 
proportions, and number of tail-feathers have all been ignored in favour of 
the view that, as the birds bore a family resemblance, they must be referred 
to one genus. If genera with any pretence to affinity be recognised, then 
Sula must be subdivided. The nomenclatural problems are too complex to 
be detailed here but wiU be fuUy discussed in my Birds of Australia. The 
species Pelecanus bassanus Linne and Sula dactylatra Lesson {cyanops Auct.) 
agree somewhat in size and coloration, but the former has twelve tail- 
feathers, the latter eighteen. The species Pelecanus piscator Linne and 
Pelecanus leucogaster Boddaert agree somewhat in size, but the former has 
sixteen tail-feathers, the latter fourteen ; the last-named disagrees entirely in 
coloration from the other three. In structural proportions these all differ 
notably. It must be admitted by every reasoning ornithologist that the 
difference between twelve and eighteen tail-feathers must be considered of 
generic import when it is realised that the former occurs in the North Atlantic 
and in the South Pacific, where it lives side by side with the latter. In the 
same manner the difference in coloration between P. leucogaster Boddaert and 
the others in itself would justify generic separation, when it is remembered 
that all the other genera and species have a uniform style of coloration which 
is quite different, and one which is practically unchanged in the same species 
with a North Atlantic, South Atlantic, and South Pacific distribution.” 
I herewith attempt to dispose of my promise as reprinted above, and 
further study has indicated facts which prove the soundness of my subdivision. 
In the Catalogue of the Birds in the British Museum, Vol. XXVI., 1898^ 
Ogilvie-Grant included all the species of the family Sulidce under one genus- 
name Sula. Eight synonyms are given and types are named against each. 
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