| OCR Text |
Show 466 PROF. HUXLEY ON THE CLASSIFICATION OF BIRDS. [Apr. 1 1, The sternum is not notched, but may present two foramina posteriorly. The clavicles are relatively weak, and may be disunited, or absent. When present, they are concave forwards as well as inwards. The tarso-metatarsus is very short in relation to the tibia, broad, and flattened from before backwards. Its outer distal articular head is divided by a groove into two articular facets. The fourth toe, articulated with this double facet, is permanently turned backwards. The basal phalanges of the second, third, and fourth digits of the foot are shorter than the penultimate. The inferior larynx has three pairs of muscles, and is, in other respects, peculiar. The contour-feathers have a large aftershaft, and the oil-gland when present has a circlet. The Parrots constitute one of the best-defined groups of birds, having affinities, though of no very close character, with the Aeto-morphae and the Coccygomorphse. 7. The COCCYGOMORPHSE. The rostrum presents very various forms, and may be moveably articulated with the skull. Basipterygoid processes are present only in one genus (Trogon). The maxillo-palatines are usually more or less spongy. The palatines are not developed into vertical plates, but are, as usual, horizontally flattened. The distal end of the quadrate bone has the ordinary form. The sternum usually presents two notches on each side, and has no bifurcated manubrial process (ex. Merops). The clavicles are convex forwards, and without any process developed backwards from the summit of their symphysis. The tarso-metatarsus is never remarkably elongated. It does not appear that anything can be predicated in common of the pterylosis or of the characters of the oil-gland in this group. The larynx has not more than one, or at most two, pair of intrinsic muscles. The Coccygomorphae are readily divisible into four groups by the characters of their feet, as follows :- a. The first toe turned forwards, as well as the others. Coliidee. h. The fourth toe temporarily, or permanently, turned backwards, as well as the first. Musophagidee, Rhamphastidee. Cuculidce. Capitonidce. Bucconidce, Galbulidee. |
