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 





Fio. 2G5. — White-tailed Ptarmigan (Logopus leucurva), in (upper figure) summer 

 and (lower figure) winter plumage. 



curassows (G'racidw), 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 (Opisthocomus cristatus). In this 

 bird the keel of the breast-bone is cut away in front, the 

 wish-bone unites with the coracoid bones, and also with 



