PUFFINUS CHLOEOEHTNCHUS. 1055 



will have crossed ahead of the ship or flown round it at a distance, making their way off to leeward, and disap- 

 pearing as rapidly as they came in sight. Their flight is performed hy swaying the body as it were from side 

 to side, with the wings outstretched, and not flapping, but turned up successively from the horizontal, the 

 course after each sudden inclination being downward and then up again with a rapid sweep, overtopping the 

 waves, and instantly dropping again into the succeeding trough of the sea. They feed on marine substances, 

 oily matter, the fat of whales when it can be procured, and any garbage they may find floating on the water. 

 They sit buoyantly on the water, and must of necessity sleep in that position, possibly reposing a good deal 

 by day. 



Nidification. — The Green-billed Petrel breeds at Round Island, Mauritius, at Rodriguez, and probably 

 other islands in the Indian Ocean. Mr. Edward Newton, who visited a breeding-place of this species at the 

 first-named island, gives an interesting account of it in the ' Ibis/ 1861, p. 181, stating that there is a large 

 colony at the north-east of the island, although they are spread over the greater part of it. He observes that 

 they are as tame as the Tropic-birds, but not so harmless. " They breed," he says, " under stones, and bite 

 most awfully if they get a chance. The only way to get them out and take their single egg is to contrive to 

 turn them round so that one can grab their folded wings and tail. If dropped on the ground they wdl run 

 about, and for some time will not try to fly ; but if thrown into the air, they will glide down gently towards 

 the sea. On going near any rock where there may be a dozen or two, one bird seems to give the alarm, and a 

 chorus of the most extraordinary sounds immediately proceeds from under ground. I hardly know what 

 to compare it to, as there is nothing like it except, perhaps, the noise made by eats when they set up their backs 

 and squall. ... It is kept up for a minute or two, and increases when the individuals are hauled out in the 

 manner above described." Two eggs of this Petrel from Round Island, for an examination of which I am 

 indebted to Mr. Foottit, of Croydon, are elongated ovals, one slightly broader than the other, and both a Uttle 

 pointed at one end; they are dull white and smooth in texture, measuring 2 - 57 by 1*51 and 23 by 1-53 inches. 



Genus DAPTIOX. 



Bill short, stout, the base rounded, with a groove running out to the tip ; sides inflated ; 

 nostrils with a single orifice, and divided inside the tube, which is flattened and slightly elevated 

 in front ; upper mandible with very shallow oblique lamellae ; gonys straight. Wings long, 

 pointed, the 1st quill the longest ; secondaries short. Tail short, of 14 feathers, and rounded at 

 the tip. Tarsus reticulate in front, compressed laterally, and shorter than the middle toe, which 

 is shorter than the outer ; hind claw stout and very short. 



Under tail-coverts very long. 



