50 Dwicut, Moult of Quatls and Grouse. se 
indistinguishable, males assuming the black throat and crest, 
females the browner dress. A male (Amer. Mus. No. 29637, 
Arizona, October 11) is acquiring a few black feathers of the 
chin patch and the chestnut feathers of the flanks, while the 
postjuvenal moult in the wing has reached the sixth primary, 
the two distal still retaining their follicles. A female (Amer. 
Mus. No. 29634, Arizona, October g) is largely in first winter 
plumage, the only old feathers of the remiges being the third 
and the three proximal; a new blue-gray tail has replaced the 
mottled one of the juvenal plumage. 
first Nuptial Plumage, acquired by a partial prenuptial moult 
limited to the anterior parts of the head and throat. Numerous 
specimens illustrate it. The black throat and its white border 
are renewed by feathers of the same color. The moult appears 
to take place in Arizona towards the end of April. 
Second or Adult Winter Plumage, acquired by a complete post- 
nuptial moult. 
Later plumages are like those already described. 
Cyrtonyx montezumez (V7g.). MAssENA PARTRIDGE. 
A fine series of twenty-seven specimens illustrates well the dif- 
ferent plumages, especially of the young bird. 
Natal Down.— Above chestnut or rusty brown, in the median 
line, mottled with dull black and bordered with buff; a dusky line 
behind the eye. Below dull white, palest on the chin. 
Juvenal Plumage, acquired by a complete postnatal moult. 
Both sexes now resemble the adult female, being streaked, but 
without the pinkish tint of the back and are black-spotted below 
with white shaft-streaks. .A male (Amer. Mus. No. 58934, Ari- 
zona, September 12) still shows down on the throat and sides of 
‘the head. ‘The juvenal rectrices are partly grown, the primaries 
are pulpy, the distal pair not yet visible, and the inner secondaries 
are still only partly developed. A female (Amer. Mus. No. 
56536, Mexico, October 12) has assumed the dull white throat of 
the juvenal dress and shows the postjuvenal moult, which has 
already involved the seventh to the thirteenth of the remiges ; the 
distal pair are not yet fully grown. Several other specimens show 
