The prevalent impression that the eggs of this Hawk are generally unspotted, so far as I am aware, is not correct. All that I have ever seen, except the eggs above referred to from Texas, and a few others, have been more or less marked with light-brown blotches. These markings are not always very distinct, but, as far as my present experience goes, they are to be found, if carefully sought. In 1856 I received from Dr. Dixon, of Damariscotta, a nest with six eggs of a Hawk of this species. The female had been shot as she flew from the nest. With a single exception, all the eggs were very distinctly blotched and spotted. In shape they were of a rather oblong-oval, rounded at both ends, the smaller end well defined. They varied in length from 2.00 to 1.87 inches, and in breadth from 1.44 to 1.38 inches. Their ground-color was a dirty bluish-white, which in one was nearly unspotted, the markings so faint as to be hardly perceptible, and only upon a close inspection. In all the others, spots and blotches of a light shade of purplish-brown occured, in a greater or less degree, over their entire surface. In two, the blotches were large and well marked; in the others, less strongly traced, but quite distinct. The nest was found in a tract of low land, covered with clumps of sedge, on one of which it had been constructed. It is described as about the size of a peck basket, circular, and composed entirely of small dry sticks, “finished off or topped out with small bunches of pine boughs.” There was very little depth to the nest, or not enough to cover the eggs from view in taking a sight across it. “No feathers were found in or about it. It was simply made of small dry sticks, about six inches thick, with about one inch of pine boughs for finishing off the nest.” The eggs were found about the 20th of May. They contained young at least two weeks advanced, showing that the bird began to lay in the latter part of April, and to sit upon her eggs early in the following month. It will be thus seen that the eggs of this Hawk vary greatly in size and shape, and in the presence or absence of marking, varying in length from 1.75 to 2.00 inches, and in breadth from 1.25 to 1.50, and in shape from an almost globular egg to an elongated oval. Some are wholly spotless, and others are very strongly and generally blotched with well-defined purplish-brown. This Hawk was found breeding in the Humboldt Valley by Mr. C. S. M‘Carthy, on the Yellowstone by Mr. Hayden, at Fort Benton by Lieutenant Mullan, at Fort Resolution by Mr. Kennicott, at Fort Rae and at Fort Simpson by Mr. Ross, at La Pierre House by Lockhart, and on the Lower Anderson by Mr. MacFarlane. GENUS NISUS, CUVIER.