OCR Text |
Show 1906.] OF THE TRACJIEOPHONE PASSERES. 153 In Philepitta the tuberculum medius, which forms a kind of penthouse roof over the pneumatic foramen, is perforated by a small hole ; and the deltoid crest is short and but feebly developed. The arm and forearm are pneumatic. The intermetacarpal plate is moderately well developed, and fuses along its hinder border with the metacarpal III., which is slender and bowed. In the Pittida? only the humerus is pneumatic. The deltoid crest is obsolete, but the crista inferior is well developed and roughly triangular in shape. As in Philepitta, there is no coraco-huineral groove, but the ectepicondylar process is better developed than in Philepitta. In the Piprida? the humerus only is pneumatic, the deltoid crest is short and feeble, and the coraco-humeral groove is wanting. At the base of metacarpal I. is a deep notch continued outwards along the preaxial border of metacarpal II. in the form of a channel for the tendon. None of the bones in the wing of the Pteroptochina? is pneumatic ; the deltoid crest of the humerus is obsolete and confined to the extreme proximal end of the shaft, and the ectepicondylar process is wanting; the intermetacarpal plate is well developed, and the preaxial border of metacarpal II. is marked by a small, laterally compressed, mound-shaped boss of bone. As in Pteroptochus, so in Hylactes the wing is non-pneumatic, and the deltoid crest of the humerus is feebly developed, while the radial and ulnar condyles are set close together. Metacarpals II. and III. are unusually broad and set close together, reducing the space between to a mere slit. Of the subfamilies Formicariina?, Dendrocolaptina?, and Synallaxina?, I can say nothing that would be of use. The wing here presents a great general similarity, and it is impossible to say, at present-owing to the lack of skeletons,-whether the slight differences which can be made out are due to individual variation, or whether they obtain throughout whole genera. viii. THE PELVIC LIMB. The pelvic limb in some respects resembles that of the Eury-la? mida?. Although the different groups herein described do not, in this matter, differ very widely one from another, yet this limb presents a greater range of variation than is found in the case of the wing. In the Piprida? only is the femur pneumatic, in this matter agreeing with the Cotingida?; the fibular crest is short, and the fibula continued far down the leg in the form of a delicate style; the cnemial crests are moderately well developed. The Ph. I. of D. IV. is less than half the length of Ph. I. D. III. The most striking feature perhaps about the Philepittida? is the oblong, more or less quadrangular shape of the entocnemial process, which rises directly from the level of the articular surface of |