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

122 BULLETIN 133, UNITED STATES NATIONAL MUSEUM
single birds. An immature individual, a male, is very brown above^
and on first glance seems to be identical in color with the adult of
cachinnans. In the northern bird immature specimens in addition
to being more extensively white below are browner above than adults^
a distinction that seems to hold in galeata as well. Though this immature
is similar to the adult of cachinnans it is darker and more
olivaceous than the immature of that form, in addition to being
less extensively white below. A second specimen is somewhat intermediate
in stage of plumage.
Measurements of these specimens, in millimeters, are as follows:
Five males, wing, 170-186 (176.5) ; tail, 66-74.2 (69.9) ; tarsus 52.5-
62.6 (57.2). Two females, wing, 164-177.6 (170.8); tail, 62.8-67.5
(65.1); tarsus, 50-56.2 (53.1).
On one of the large lagoons at the Riaclio Pilaga gallinules were
common, and when first seen as they were swimming about in open
water at a distance I mistook them for coots. An Indian to whom
I appealed for a boat quickly fashioned a crude pointed raft with
three or four armloads of tall, green cat-tails, bound together with
a few of the tougher stems, and on this somewhat precarious craft
I paddled out to explore the lagoon. The gallinules were shy but
by working up behind concealing points of rushes I succeeded in
shooting several, as well as a grebe, before all had flown or swam
into shelter of the rushes. A few days later an Indian brought me
more that he had killed at the same place.
At Rio Negro, Uruguay, on February 18, 1921, the birds were
common in the vegetation concealing the water of a small lagoon.
Near Tunuyan, Mendoza, two were recorded March 26.
PARDIRALLUS RYTIRHYNCHOS RYTIRHYNCHOS (Vieillot)
Rallus rytirhynclios Vieillot, Nouv. Diet. Hist. Nat., vol. 28, 1819, p. 549.
(Paraguay.)
Eight specimens of this species were secured, six of Avhich were
preserved as skins, one as a skeleton, and one in alcohol. An adult
male from Lazcano, Uruguay, shot February 7, 1921, and an adult
male from Rio Negro, Uruguay, taken Februaiy 18, differ constantly
from a series from Buenos Aires in darker, duller coloration. It is
possible that these should be separated as typical rytirhynchos and
that the Argentine birds represent another form. These birds vary
individually to such an extent that a considerable series will be
needed to establish or disprove this point. An adult male from
General Roca, Rio Negro, in northern Patagonia, taken December 3,
1920, and two males and a female from Tunuyan, Mendoza, secured
March 23, 25, and 28, 1921, agree in color and are similar to others
from Argentina.