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Show 1905.] OSTEOLOGY OF THE EURYLJEMUXE. 49 metacarpal III. In the Eurylaemidae this spur is, however, much larger than in the Coraciiform genera referred to. The humerus only is pneumatic ; and is subequal to, or shorter than, the manus. The forearm is the longest segment of tlie limb. The sulcus transversum or coraco-humeral groove is shallow. The crista superior is triangular in form. The incisura capitis is fairly sharply defined ; the fossa subtrochanterica is large. There is a small ectepicondylar process, which, it is to be noted, is not forked as in the higher Passeres ; the entepicondylar process is still smaller. Ventrad of the tuberculum ulnare is a prominent spur-like blunt-pointed tubercle directed backwards and outwards so as to interlock with the olecranon process of the ulna in the extended wing. On the palmar surface immediately above the radial condyle is a small tubercle for the attachment of the inner head of the extensor metacarpi ulnaris. The ulna has a prominent, pointed, olecranon process, and bears a row of small tubercles, for the attachment of the secondary remiges, along its postaxial border. The radius is slender and slightly bowed. The forearm is the longest segment of the wing. The manus is well developed. As in the Capitonida? and the normal Passeres, the base of Me. II. sends backwards a bony plate to overlap and fuse with the base of Me. III. In the Eurylaemida? this plate (intermetacarpal plate) is of considerable size, its base extending down the shaft for some distance. In some Coraciae, e. g. Eurystomus, there is also an intermetacarpal plate, but feebly developed, and not fused with Me. III. ix. T he P elvic L imb. The pelvic limb, in the Eurylaemidae, has, in common with the Cotingidae, a syndactyle pes ; and in this respect these two families resemble many of the Coraciiformes. None of the bones are pneumatic; in which respect the Eurylaemidae differ from the Cotingidae, which have a pneumatic femur, and resemble many of the Coraciidae. The femur is long and slender. The popliteal fossa is represented only by a shallow depression. The tibio-tarsus has moderately well-developed ecto- and ento-cnemial crests and a long fibular crest. The shaft is curved first forwards, then inwards, so that the distal end thereof is markedly inflected. The extensor bridge is ossified. The intercondylar gorge is deep. The fibula extends to below the level of the middle of the shaft of the tibio-tarsus. The tarso-metatarsus is moderately long. The hypotarsus is complex. The distal end of the shaft is flattened from before backwards, and laterally expanded to form the condyle for digits I I - IY . These condyles all extend forwards to practically the same level, the middle condyle scarcely projecting beyond the level P roc. Z ool. S oc.- 1905, V ol. II. No. IV 4 |
