PETRELS. 43 
Order IX. PROCELLARIIFORMES. Perrret-trise. 
The Albatroses and Petrels bear a strong superficial resemblance to 
the Gulls, to which, however, they are not even remotely related. They 
may be distinguished by the curious shape of the nostrils, which have 
tubular openings, while in the Gulls these are slit-like. The various 
members of this Order vary greatly in size, the Albatroses, which are 
the largest of the Petrels, possessing a wider spread of the wing than 
any other known bird, while the Storm-Petrels are hardly larger than 
a Swallow. All are endowed with great powers of flight and have a 
peculiar musky odour, specially noticeable in the Giant and Fulmar 
Petrels. The Albatroses build a fairly substantial nest and breed in 
vast colonies in the open, but the great majority of Petrels deposit their 
single egg in holes and crevices of the rocks or in burrows, using little 
or no lining. The egg is dull white, often marked, especially in the 
smaller species, with a ring of reddish spots round thelargerend. The 
young when’ hatched are covered with thick white or grey down, and 
are for a long time helpless and dependent on the care of their parents. 
Family I. DiomepEipm. ALBATROSES. 
The Albatroses, of which three genera and about fifteen species are 
recognised, are the most powerful of all birds on the wing. One of the 
largest and best known species is the Wandering Albatros (Diomedea 
exulans) ($55), which measures nearly eleven feet across the expanded 
wings. This bird breeds in great colonies on the high table-lands of 
some of the islands in the Southern Ocean, repairing there in October 
and building a mound of mud and grass with a slight hollow in the top. 
The single egg is not hatched till January, and the young is for a long 
time helpless and covered with thick white down, as may be seen in the 
young Royal Albatros (D. regia) (857). The immense expanse of the 
wings in flight is seen in the rare White-winged Albatros (D. chionoptera) 
(358) exhibited at the top of the Case. It is interesting to note that a 
specimen of the Black-browed Albatros (D. melanophrys) (856) was 
captured in Cambridgeshire in 1897. Other species of the family are 
the Yellow-nosed Albatros (Thalassogeron chlororhynchus) (859), and the 
Sooty Albatros (Phebetria fuliginosa) (360). 
Family I]. Procetnariipa#. PrtTress. 
The most aberrant of the Petrels are undoubtedly the three species 
included in the subfamily Pelecanoidine or Diving Petrels, which are 
represented by Garnot’s Petrel (Pelecanoides garnoti) (861). Like the 
Little Auk (404) (Case 24), which they closely resemble in general 
appearance, they have a hurried flight and dive into the sea in pursuit 
of their prey without any interruption in the action of their wings, and 
emerge from beneath the surface flying. Unlike the other Petrels, they 
are generally found singly or in pairs and nest sporadically. 
[Cases 
23, 24.] 
[Case 25, ] 
[Case 23.] 
