_Hydrobata_, VIEILLOT, Analyse, 1816 (Ag.).—BAIRD, B. N. A. 229.
_Cinclus_, BECHSTEIN, Gemein. Naturg. 1802. (Not of Moehring, 1752.
Type _Sturnus cinclus_, L.)—SALVIN, Ibis, 1867, 109. (Monograph.)
[Line drawing: _Cinclus mexicanus._
8117]
GEN. CHAR. Bill without any bristles at the base; slender, subulate;
the mandible bent slightly upward; the culmen slightly concave to near
the tip, which is much curved and notched; the commissural edges of
the bill finely nicked towards end. Feet large and strong, the toes
projecting considerably beyond the tail; the claws large. Lateral toes
equal. Tail very short and even; not two thirds the wings, which are
concave and somewhat falcate. The first primary is more than one
fourth the longest. Eggs white.
[Illustration: _Cinclus mexicanus._]
The slightly upward bend of the bill, somewhat as in _Anthus_, renders
the culmen concave, and the commissure slightly convex. The maxilla at
base is nearly as high as the mandible; the whole bill is much
compressed and attenuated. The lateral claws barely reach the base of
the middle one, which is broad; the inner face extended into a horny
lamina, with one or two notches or pectinations somewhat as in
_Caprimulgidæ_. The stiffened sub-falcate wings are quite remarkable.
The tail is so short that the upper coverts extend nearly to its tip.
The species are all dull-colored birds, usually brown, sometimes
varied with white on the head, back, or throat. They inhabit
mountainous subalpine regions abounding in rapid streams, and always
attract attention by their habit of feeding under water, searching
among the gravel and stones for their insect prey.
The only other species at all allied to the single North American one
are the _C. ardesiacus_ of Central America, and _C. pallasi_ of
Eastern Asia. They may be easily distinguished by the following
characters:—
Plumage beneath scarcely lighter than that above; head and neck
brownish, darkest above. Wing, 4.00; tail, 2.15; bill, .50;
tarsus, 1.20; middle toe, .85. Legs (in life), pinkish white
(8,496 Fort Mass. N. M.). HAB. Mountains of Middle Province from
Sitka, south to Guatemala … var. _mexicanus_.
Plumage beneath much lighter than that above,—very light along
the median line; head not brownish, the contrast in shade between
upper and lower surfaces very marked. Wing, 3.50; tail, 2.05;
bill, .45; tarsus, 1.30; middle toe, .90. Legs yellow. (42,788 ♂
Costa Rica). HAB. Guatemala and Costa Rica. …
var. _ardesiacus_.[24]
Plumage uniform dusky-brown, middle of belly blackish; _back and
rump squamated with black_; wings and tail blackish-brown. Total
length, 8.00; wing, 4.00; tail, 2.50; tarsus, 1.25; bill (to
rictus), 1.10 (Salvin). HAB. Lake Baikal to Kamtschatka;
Amoorland; S. E. Siberia; Japan (Salvin) … var._pallasi_.[25]
Cinclus mexicanus, SWAINS.