Other writers also agree in representing this Hawk as heavy and sluggish in habit, and as frequenting streams of water, and its food as consisting chiefly of the reptiles and smaller animals which frequent the banks of rivers and creeks. It builds its nests on low trees, in the immediate vicinity of its hunting-ground, and often over the water, constructing them of coarse flags and water-plants. The nests are usually not very large for the birds, are flattened or with very slight depressions, and the materials are very loosely put together. The eggs are from three to five in number, usually white and unspotted, occasionally with more or less of a yellowish or tawny tinge. In some instances they are faintly marked with light dashes or stains of a yellowish-brown, and, more rarely, are also marked with small blotches of sepia-brown, and with smaller dottings of purplish-drab. Their average measurement is, length 2.13, breadth 1.69 inches. Our knowledge of the eggs of these Hawks is derived from the collection of the late Dr. Berlandier, of Matamoras, in the Province of Tamaulipas, Mexico. In the cabinet of that gentleman were several varieties, now in the possession of the Smithsonian Institution, and presented to it by Lieutenant Couch. [Illustration: _Onychotes gruberi, Type,_ (=41703.= _California._)] [Illustration: =41703= ¼ ½ _Onychotes gruberi._] GENUS ONYCHOTES, RIDGWAY. _Onychotes_, RIDGWAY, P. A. N. S. Philad. Dec. 1870, 142. (Type, _O. gruberi_, nov. sp.) GEN. CHAR. Bill short, the tip remarkably short and obtuse, and only gradually bent; cere on top about equal to the culmen, very broad basally in its transverse diameter, and ascending, in its lateral outline, on a line with the culmen; commissure only faintly lobed. Nostril nearly circular, with a conspicuous (but not central or bony) tubercle; cere densely bristled below the nostril, almost to its anterior edge; orbital region finely bristled. Tarsus very long and slender, nearly twice the length of the middle toe; toes moderate, the outer one decidedly longer than the inner; claws very long, strong, and sharp, and curved in about one quarter the circumference of a circle. Tibial feathers short and close, the plumes scarcely reaching below the joint. Feathers of the forehead, gular region, sides, and tibiæ, with white filamentous attachments to the end of the shafts. Wing very short, much rounded, and very concave beneath; fourth quill longest; first shorter than ninth; four primaries emarginated, and one sinuated, on inner webs; five sinuated on outer webs. Tail about two thirds as long as wing, rounded. Outstretched feet reaching beyond end of tail.