424 



PEOCELLARIINiE. 



PETRELS AND ALLIED SPECIES. 



The Procellariina?, some of whicli arc of gigantic, and 

 others of very diminutive size, are oceanic birds, of whicli no 

 general definition has been given by any author known to 

 me. It is very easy to inform us that the mariner meets with 

 them far from land, and that ornithologists are now pretty 

 well agreed as to the forms that ought to be included in the 

 group, or to present a long survey of heterogeneous and dis- 

 cordant opinions on the subject ; but the question with us is^ 

 what are the Procellariinse ? 



They are mersatorial birds distinguishable by a peculiarity 

 in the disposition of their nostrils, which are more or less 

 tubular and dorsal, and still more by an enormous dilatation 

 of the proventricular portion of their oesophagus, which, 

 when filled, occupies by fiir the greater part of their abdomi- 

 nal cavity. Any bird presenting these two characters may 

 be at once referred to the Procellariina?. 



Otherwise, they differ from each other in size and propor- 

 tions ; but may be generally described as having the body 

 ovate ; the neck of moderate length ; the head rather large ; 

 the bill not longer than the head, moderately stout, com- 

 pressed ; the vippcr mandible with the ridge formed of two 

 generally united plates, at the anterior end of which are the 

 nostrils, the tip decurved, compressed, and pointed ; the 

 edges of both mandibles sharp ; the tip of the lower with its 

 edges decurved. 



The mouth is wide and dilatable ; the palate longitudinally 

 ridged ; the tongue tapering, pointed, flat above ; the oeso- 

 phagus of moderate Avidth along the neck, but Avithiu the 

 thorax dilated into an enormous sac ; the stomach, on the 



