ZOOLOGICAL MUSEUM, TRING. 
39 
well as other duties. These facts, however, are not 
sufficiently studied ; but a parallel case is known to 
occur in the Turnicidae, or Hemipodes, a group of 
tiny Game Birds. 
Of the family Cuculidae only one is a true British 
bird, our Common Cuckoo, Cueuluscanorus-, while exam- 
ples of the Great Spotted Cuckoo, Coccystes glandarius, 
and the American Yellow-billed Cuckoo, Coccyzus 
americanus, as well as the Black-billed Cuckoo, 
C. erythrophthalmus, have been shot in the British 
Islands ; bat such cases are very rare, and, with ex- 
ception of the first, probably due to human assistance. 
The Woodpeckers, Picidae, are below the Cuckoos. 
The British species, the Black, Spotted, Green Wood- 
peckers, are well represented. Varieties and albinoes 
are rather rare in this family, but a pale isabelline 
variety of the Continental Picus canus is to be seen. 
The Parrots, an entirely tropical family, are absent 
from Europe, but well known to everybody from 
being frequently kept alive. Many species are chiefly 
of green plumage, and it is remarkable that their 
albinoes are not white, but sulphur-yellow ! This 
seems to be a general law among green birds, for 
Mr. Rothschild has also received a yellow albino of 
a green Himatione from the Sandwich Islands; while, 
on the other hand, albinoes of the grey West African 
Parrot are white ! The Toucans, Rhamphastidae, are 
all South American, and easily known by their enor- 
mous but thin, light, and hollow bills. The Barbets 
