OCR Text |
Show (il) MR. ST. GEORGE MIVART ON HEMICENTETES. [Jail. 17, Fig. 2. Upper view of skull, twice the size of nature. There is no ridge or other process at the front of the orbit. As has been said, there is no sagittal crest, but a tolerably developed lambdoidal one which extends across from one glenoid surface to the other. The temporal fossa is much smaller than in Centetes ; and the concavity which exists in the last-named genus, above and in front of the first upper premolar, is wanting in Hemicentetes. There is no marked concavity above the anterior opening of the infraorbital canal, or in the summit of tbe cranium between the orbits. The palate is very long and narrow, but of less equal width than in Centetes, expanding laterally to a greater degree from before backwards. Its posterior margin is not at all or only very slightly thickened (without any transverse bony plate behind such thickening when present), and with a deep, sharp median notch. The palate projects backwards considerably beyond the last molar; it is but very slightly concave antero-posteriorly, and has no median ridge running in that direction, nor anv defects of ossification. Base of skull, twice the size of nature. Pterygoid fossae cannot be said to exist, the ecto-pterygoid ridge not developing into a descending plate of bone, although distinctly perforated posteriorly. The pterygoid descends as a triangular lamella of bone ending in a delicate backwardly, downwardly, and outwardly directed hamular process. The meso-pterygoid fossa slightly narrows as it proceeds backwards, but does not end pos- |