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Show 1899.] CRANIAL OSTEOLOGY OF THE PARROTS. 19 Chrysotis and the Macaws. The orbit is of remarkably small size, its antero-posterior diameter being about equal to that" of Psittacus erithacus, and a little less than that of Eclectus cardinalis. The squamosal process is large and flattened; it runs parallel to the posterior portion of the suborbital ring, and the temporal fossa between is unusually deep and wide. The suprameatal process is large, and overhangs a deep groove or hollowed plate of bone that Fig. 9. Stringops habroptilus : part of the skull of a young individual, for comparison with figs. 4, 5, 6. lies posterior to the quadrate articulation and above the auditory meatus, roofing over the superior auditory recess ; it is comparable to, though far smaller than, the remarkable area connecting the auditory cavity with the hollowed surface of the squamosal in Nestor. The anterior border of this bony plate forms a well-defined margin to the quadrate articulation, which is thus very distinctly separated from the auditory cavity. The auditory meatus is rounded and wide open ; its posterior wall scarcely diminishes its aperture. The basitemporal plate is on a level with the occipital condyle; its edges are formed by elevated ridges that run back to the nearly vertical paroccipitals, and the lateral areas continued forwards from these latter are sharply inclined. The intraorbital vacuities are very large. The quadrate bone (fig. 10) is especially remarkable, and Fig. 10. Quadrate bone of Strinyops. in it the Psittacine type of quadrate is imperfectly attained. The shaft of the bone is shorter and less vertical than usual, the 2* |