Page:Condor16(4).djvu/14

 172 THE CONDOR Vol. XVI what for individual eggs, as does also the form in different specimens. As to the white, chalky deposit, it by no 'means always obscures the pale blue ground color of the egg, for in some the layer is extremely thin, while in others it may have been more generously applied or deposited on the surface, some- times even in heavy circumscribed blotches (see no. 2). Two eggs of this grebe are given in figure 50 with this article (nos. i and 2); they are from the Court collection, and were taken by A. O. Treganza at Utah Lake, Utah, on the 29th of May, 1904 (set mark 29-4). Mr. Treganza, who resides at Salt Lake City, describes the nest as being a "platform of reeds, partly floating, partly resting on broken-down reeds; nest proper com- posed of decayed reeds. Water three to six feet deep." The colony of grebes, where these eggs were collected, was located about two miles from the shore, and contained about one hundred nests. Some of the clutches were in advanced incubation. Eggs from the other nests are be- fore me, but their characters are the same as those already given for the specimens shown in the figures. Passing to Colymbus holboelli, a grebe of which I have several eggs at hand belonging to the Court collection, it is to be noted that they very closely resemble those of the Western Grebe just described (fig. 50, nos. 3 and 4). They are, however, somewhat smaller, a fact noted by Ridgway in his Manual ("Eggs 2-5, 2.23xl.37," p. 5.) Coues on the other hand says, in the last edition of .his "Key": "Eggs 2-5, sometimes more, oftener 3 or 4, 2.10-2.35xl.51.-1.45, rough, whitish, either inclining to pale greenish or with buffy discoloration, of the narrow-elongate shape usual in this family" (p. 1056). That they are not always of the "elon- gate shape," will be appreciated by comparing nos. i and 3 of this paper. The "buffy discoloration" is to be attributed to stains due to coming in contact with the decaying vegetation composing the nest. Mr. William B. Arnold col- lected the eggs of the Holboell Grebe shown in nos. 3 and 4 of fig. 50 (Mani- toba, Canada, June 15, 1910). Reed, in his above cited book, says of the eggs of the Holboell grebe: "They lay from three to six eggs of a dingy white color which have the stained sur- face common to Grebes' eggs, size 2.35xl.25." Those shown in nos. 3 and 4 of the present article are somewhat larger than this, though very slightly so. There is considerable chalky deposit on no. 4, while no. 3 has hardly any, and is of a very pale greenish shade. I have not illustrated the egg of the Horned Grebe (Colymbus auritus), but a specimen of it is shown in Reed's "North American Birds' Eggs" (p. 2), and he says in regard to this species: "They build a typical Grebe's nest, a floating mass of decayed matter which stains the naturally white eggs to a dirty brown. The number of eggs varies from three to seven. Size 1.70x1.15." To represent Colymbus nigricollis, I have selected eggs of the Eared Grebe (C. n. californicus), and two of these are shown in fig. 51, nos. 7 and 8. They are typical for this species, and I have several of them at hand from Mr. C0urt's collection. Mr. A. 3/I. Ingersoll took them at Lake San Jacinto, Riverside Coun- ty, California, on the 8th of June, 1897. At the time they were collected there were many nests there with eggs of this bird in sight. The floating nests were attached to growing grass in about fifteen inches of water (set mark 2021, no. 4). Coues says of the eggs of this grebe that they are "not dis- tinguishable from those of C. auritus" (p. 1058); while Reed (loc.