224 
ZOOLOGY, 
sand three or four feet deep in the beaches of the Celebes 
Islands, the birds going down for this purpose ten or fifteen 
miles from the interior; and returning again, leaving the 
eggs to hatch and the young to shift for themselves. (Wal- 
lace.) 
The megapods, together with the American guans and 
Fia. 265.— White-tailed Ptai-migan {Lagopus leucurvs), in (upper figure) summer 
and (lower figure) winter plumage. 
curassows {Cracidce), form a sort of passage from the gal- 
linaceous to the columbine birds. One of the most puz- 
zling forms for the systematic ornithologist to deal with is 
the hoasin of Guiana {Opistliocomus cristatits). In this 
bird the keel of the breast-bone is cut away in front, the 
-^ish-bone unites with the coracoid bones, and also with 
