Bulletin - United States National Museum - si-pddr - Smithsonian ...

174 BULLETIN 133, UNITED STATES NATIONAL MUSEUM
A young bird half-grown, collected December 8 at Zapala, has
most of the original covering of down rej^laced by the immature
plumage, though much down still persists on the head. Adult
males in somewhat worn plumage were taken December 8 and 9.
One of these had the gonys, culmen, and tip of the bill dull black;
remainder of maxilla deep olive buff ; remainder of mandible vetiver
green ; nasal operculum deep neutral gray ; iris Rood's brown ; tarsus
and toes chamois. A male and a female preserved as skins from
Concon are in full fall plumage. Specimens were preserved in
alcohol and as skeletons.
The curious opercular flap that covers the nostril in the seed snipe
is an undoubted protection against wind and sand to a bird that
much of the time inhabits regions where protective cover is scant
and strong winds carry clouds of dust. It may be remarked that
the Pteroptochids Rhinocrypta and Teledromas that inhabit the
same areas have developed a very similar structure.
Order COLUMBIFORMES
Family COLUMBIDAE
LEPTOTILA OCHROPTERA OCHROPTERA (Pelzeln)
Leptoptila ochroptera Pelzeln, Ornith. Brasiliens, pt. 3, January, 1870,
p. 278. (Sapitiba, Brazil.)
After comparison of a fair series of pigeons of this species from
southern Brazil, Paraguay, and Uruguay, I am able to distinguish
the typical subspecies from cJilorauchenia only by size, as in the
series at hand color differences seem variable. Northern birds
usually are duller in color on the abdomen than those from the south,
a difference that perhaps is constant in fresh specimens, but is sub-
ject to variation with age, as younger individuals are duller than
those that are older. Specimens also discolor with time, so that those
taken 30 or 40 years ago are not comparable with fresh material.
Males of L. o. ochroptera have the wing 146 to 148.5 mm. (specimens
from Kilometer 182, Formosa, and upper Paraguay) ; females
135.5 to 142.5 mm. (Jaboticabel, Sao Paulo; Puerto Pinasco, Paraguay;
Rio Bermejo, above its mouth, Argentina).
In Leptotila o. chlorauchenia the wing in males measures from
153 to 158 mm. (specimens from Rio Grande do Sul, Brazil; Laz-
cano, Uruguay; Las Palmas, Chaco; Conchitas, Buenos Aires); in
females from 150.5 to 153.3 (San Vicente, Uruguay; Las Palmas,
Chaco.) Specimens from Las Palmas, Chaco, near the Rio Para-
guay, are the southern form. Two from Kilometer 182, in the in-
terior of the Formosan Chaco, have the measurements of the north-
ern form but are intermediate in color, since one is light and the