--Audubon's (1966: plate 409) original painting of the Common Loon (Gavia immer) shows only the upper surface of the left foot of a loon in breeding plumage. The foot is mostly black, with gray on the toes and in the center of each web. Gromme (1963: 3) painted the feet of a breeding Common Loon a uniform gray. Most other artists have painted the loon swimming, sitting on a nest, or in flight without the feet or legs showing. Wilson (1840: 651) noted "the outside of the legs and feet is black, inside pale blue." Maynard (1881: 493) on the other hand thought that the Fig. 1. Upper: Medial viexv of closed Common Loon foot. Lower: Outer view of closed Common Loon foot. feet of adults were greenish and that those of nestlings were black. Gabrielson and Lincoln (1959: 53) suggest that in breeding plumage the feet are black, and that in fall and winter plumage they are dusky reddish flesh colored. Dement'ev and Gladkov (1968: 295) report that the feet of the Common Loon are "brown with yellowish or greenish tinge on exterior surface of tarsometatarsns and third and fourth toes." Palmer (1962: 22) records the legs of the Common Loon as "black on outer side paling to medium gray on inner; webs of feet dark with flesh colored centers." Bannerman (1959: 272) reports "The tarsus is black externally and whitish internally." Finally, Witherby et al. (1941: 117) stated "legs and feet (ad.) outside nearly black, inside very pale grey, webs same with flesh-coloured centres, (juv.) paler, outside dusky, inside milky blue-white." Perhaps still other descriptions of the leg and foot color of Common Loons exist, but clearly ornithologists who have written about or painted loons fail to agree on it. Since 1970 I have examined five Common Loons found dead on Mississippi, Alabama, and Florida beaches, and one live loon found entangled in nylon fishing line. Some of the loons were still in winter plumage (e.g. MSU No. 700, male, 8 March 1973, Santa Rosa Island, Santa Rosa County, Florida) and others were in breeding plumage (e.g. MSU No. 813, male, 6 April 1974, Dauphin Island, Mobile County, Alabama); all had feet and legs colored similarly (Figs. 1 and 2). The medial surface of each leg was white; the outer side was black. The feet were also distinctly black and white such that when the webs were not stretched, that portion of the foot exposed mediaBy was white and that portion exposed to the outside was black (Fig. 1). This pattern includes the nails, most of each being white, but the edge exposed to the outer side being black. With the web extended (Fig. 2) most of the upper surface of the foot was white, though that part of the web closest to each toe was black, shading to white. The plantar surface of each foot was mostly black, with only the center of each web white. Study of the living bird found tangled in nylon line revealed how this color pattern Fig. 2. Left: Dorsal view of Common Loon foot. Right: Plantar view ot Common Loon foot. contributes to the overall countershading of the loon. When the loon was relaxed in the water, its feet extended posteriorly, the white medial surface of the leg and upper surface of the foot were visible from below, and the black surfaces visible from above. It seems plausible that the loon is thus camouflaged by blending in with the dark bottom when viewed from above and with the light sky when viewed from below and as a result potential prey are less likely to see the loon until too late. Sutton's (1943) drawing of a Red-throated Loon (Gavia stellata) clearly shows the outside of the tarsus dark and the inside pale. His (Sutton 1963) description of the feet and legs of the Yellow-billed Loon (Gavia adarnsii) adult and day- old chick also suggest a color pattern similar to that of the Common Loon. As with the upside-down catfish (Synodontis spp.) (Marshall 1966: 185) the foot of the loon is intriguing because the pattern of countershading is anatomically reversed (the dorsal surface is light) though, because of the bird's behavior, it exemplifies the principle of countershading (Thayer 1918). .ks with flesh colors in most birds, the white on the legs and feet of my specimens darkened within a few days after death to a yellow- or gray-brown. Although possibly leg color may vary geographically, seasonally, or with age, apparently many previous workers have not relied on fresh specimens for their descriptions and paintings. LITERATURE CITED AU)UBoN, J. J. 1966. The original water-color paintings of John James Audubon for the birds of America. New York, Amer. Heritage Publ. Co., Inc. B^VER^N, D. 1959. Birds of the British Isles, vol. 8. London, Oliver and Boyd. DEE'EV, G. P., ^m N. A. G^)ov (Eds.). 1968. Birds of the Soviet Union, vol. 2. Jerusalem, Israel Program for Sci. Transl. G^BRmLSO, I. N., ^m F. C. LncoL. 1959. Birds of Alaska. Harrisburg, Penn- sylvania, The Stackpole Co. GROrE, O. J. 1963. Birds of Wisconsin. Madison, Univ. Wisconsin Press. M^RS^LL, N. B. 1966. The life of fishes. Cleveland, Ohio, The World Publ. Co. M^3/4^RD, C. J. 1881. The birds of eastern North America. Newtonville, Massa- chusetts, C. J. Maynard & Co. P^nER, R. S. (Ed.). 1962. Handbook of North American birds, vol. 1. New Haven, Connecticut, Yale Univ. Press. SJTTO, G. M. 1943. The wing molts of adult loons: a review of the evidence. Wilson Bull. 55: 145-150. SJTTOS, G. M. 1963. On the Yellow-billed Loon. Wilson Bull. 75: 83-87. TH.3/4E, G. H. 1918. Concealing-coloration in the animal kingdom. New York, The Macmillan Co. Wnsos, A. 1840. Wilson's American ornithology. Boston, Otis, Broaders, and Co. WTIIERB3/4, H. F., F. C. R. JOURDAIN, N. F. TcJs:r, A) B. W. TJCKR. 1940. The handbook of British birds, vol. 4, London, H. F. & G. Witherby Ltd. Jo A. JAcxso, Deparmen of Zoology, Mississippi Sate University, Missis- sippi State, Mississippi 39762. Accepted 19 Feb. 75.