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. AMERICAN DIPPER; WATER OUZEL.