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 170 THE CONDOR Vol. XV! For the material used in the present connection I am again indebted to Mr. E. J. Court of Washington, D.C., from whose fine collection of eggs most of it has been selected,,and also to the United States National Museum for the loan of three exceptionally beautiful eggs of our Common Loon (Gavia immer), here figured in nos. 11-13. All the photographs of the eggs illustrating the present article are reproductions of those made by myself, direct from the specimens shown, and all are natural size on my negatives. It will not be necessary to list here the grebes and loons known to occur in our avifama, for they are familiar to ornithologists everywhere. The eggs of all of them have been examined and compared by me during the prepara- tion of the present paper, with the exception of the eggs of the Yellow-billed Loon (Gavia adamsi), no specimens of the eggs of which are to be found in either of he above referred to collections; I shall refer to this matter again farther on in this article. Throughout the early literature of the grebes in this country, there exists no little confusion in regard to the American species, a statement that may, in most instances, be extended to include the descriptions of their nests and eggs. They are better known now, and the first form here to be noticed is the Western Grebe, the Podiceps occidentalis of Lawrence and the -/Echmophorus occdentalis of the A. O. U. Check-List. It has a wide range through western North America, occurring as far south as central Mexico. No descriptions of grebes are found in Wilson's "American Ornithology", though five species of them are listed at the end of the "Brewer's Edition" of that work. Audubon's accounts of our grebes are scanty and of but little value. The most elaborate one is devoted to the Crested Grebe ("Podjeeps cristatus"), a bird not found in North America, but which he claims to have met with in numbers over the greater part of the United States in his time. Ridgway says of this bird in his Manual: "Ne, arly cosmdpolitan, but no authentic record for any portion of America" (p. 5). To return to zE. occidentalis, the last-mentioned writer does not describe its eggs in the work named, sinply stating: "Eggs 2-5, 2.40 x 1.54." Not a word as to their form or color. With respect to this, Coues gives a' general description of the eggs of the North American grebes, intended to cover those of all our species, thus: "The egg are more numerous than in other pygopodous birds, frequently number- ing 6-8; elliptical, of a pale or whitish unvariegated color, and commonly cov- ered with chalky substance."2 He says, in the case of zE. occidentalis, that they are "usually 3-5 in number, measuring 2.40xl.55." Of this species Reed says: "They lay from three to five eggs, the ground color of which is a pale blue; this color is, however, always concealed by a thin chalky deposit, and this latter is frequently stained to a dirty white. Size 2.40 by 1.55.' '8 Of the seven or eight eggs of the Western Grebe before me, I find the average measurement to be almost exac.tly 2.40xl.55, though this varies some- 2. COUES, E. Key to North American Birds, vol. xx, fifth edition, p. 1053. He gives a separate description for the eggs of Colymbus aurftus, and states that those of C. n. californicus cannot be distinguished from them (p. 1058). 3. REED, CHESTER A. North American Birds Eggs. NewYork, 1904, p. 1. A good figure of the egg of Echmophoru$ is given; and, as a matter of fact, this excellent book is beautifully illustrated all the way through with reoroductions of photographs of the vast majority of the eggs of United States birds and many of their nests, etc.