Oedee viil— procellakiifoemes. 
The Order Procellariiformes consists of sea-birds which can be recognised 
at sight by their prominent tubular nostrils (hence the name Tubinares, by 
which the group is frequently called) and peculiar bills, which are made up of 
several horny pieces, between which are grooves. 
They constitute such a distinct group that systematists have long been in 
doubt as to the value of the aggregation, but it is now generally conceded that 
they must be recognised as a separate Order. Moreover their relationships 
appear to be with the Pelicanijorines and Spheniscifonnes, and not with the 
Lariformes, to which they bear a superficial resemblance, and next to which they 
were placed in the system I adopted before the commencement of this work. 
The inter-relationships of the higher groupings are not at all well known, as 
Salvin accepted four families in the Catalogue of the Birds in the British Museum, 
and this arrangement was followed in the Monograph of the Petrels recently 
published. But in the introduction to the latter work (p. xvii.) Pycraft 
concludes that osteologically, two families alone are recognisable. In our 
present imperfect knowledge of the group, the former classification is the 
more convenient, and I am therefore following it. The minor groupings are 
even more unsatisfactory, as almost each well-defined species is characterised 
by features which have at times been considered worthy of generic rank. 
The majority of specimens at present in museums are birds killed at sea, 
and until a series of all the various forms are collected at breeding-stations 
we cannot hope for much progress. The study of sea-killed specimens has 
caused the lumping of many distinct forms, the observed differences being 
ascribed to variability, whereas I am convinced that these birds show little 
variation when breeding series are examined. I also anticipate that, when 
this group is studied by means of breeding birds, it will be found^ that they 
are not the great wanderers they have hitherto been considered, but that the 
majority pass their time quite close to the breeding -ground. 
I have here gratefully to acknowledge that the Hon. Walter Rothschild, 
with his usual generosity in the cause of science, has placed at my disposal the 
whole of his magnificent collection of birds of this Order, to aid in working out 
VOL. II. 
1 
