342 



TTJBINAEES. 



The majority of the species lay their single egg in holes burrowed 

 in the ground, often on the lofty summits of oceanic islands. Others 

 make a nest in the open. 



The egg of each species is wholly white, or with the addition of 

 an indistinct zone of small reddish freckles near the end. 



The young are helpless till fully grown, and are covered with 

 thick down, amongst which the featliers gradually appear. 



The sexes are alike in the colour of their plumage. In some 

 species considerable variation of colour exists in different individuals 

 without apparent reference to age or sex. In a few species, such, 

 as the true Uiomedea exulans and D. alhatrus, the young are very 

 differently coloured from the adult. 



Synopsis of the Families. 



a. Nostrils united externally above the culmen ; 

 margin of the sternum even ; no pterygoid 

 processes ; manubrium of furcula long ; 

 coracoids long, comparatively narrow across 

 the base and slightly divergent ; 2nd pri- [p. 343. 



mary the longest 1. Procellariidae, 



h. Nostrils united externally, or nearly so, above 

 the culmen ; margin of the sternum uneven ; 

 distinct pterygoid processes ; manubrium of 

 furcula very short ;' coracoids short, wide at 

 the base and divergent ; 1st primary the [p. 368.. 



longest, or not shorter than the 2nd .... 2. Puffinidae, 



e. Nostrils distinct, opening upwards on 

 either side of the middle of the base of the 

 culmen ; margin of the sternum even, the 

 sternum itself considerably longer than 

 wide ; distinct pterygoid processes ; manu- 

 brium of furcula very short ; coracoids long, 

 narrow at the base and nearly parallel ; 2nd [p. 437. 



primary slightly the longest 3. Pelecanoididse,. 



d. Nosti'ils lateral, separated by the wide cul- 

 men, each in a separate horny sheath 

 opening forwards ; margin of the sternum 

 uneven, the sternum itself short com- 

 pared with its width ; no pterygoid pro- 

 cesses ; manubrium of furcula very short ; 

 coracoids short, very wide at the base 

 and widely divergent ; 1st primary the [p. 440, 



longest 4. Diomedeidae, 



