OCR Text |
Show 468 PROF. ST.-GEORGE MIVART ON THE ALUROIDEA. [June 6, Crossarchus, where it may be only imperfectly enclosed by bony processes). It may be entirely absent, as in the Felida, Galidictina, Euplerina, and Hyanida. It may occasionally be present where it is normally absent, as in Viverricula. There may be no carotid canal (for the internal carotid artery), as in the Felida; or there may be a distinct canal, as in all other iEluroids. The hinder aperture of this canal may be placed at about the middle of the internal margin of the auditory bulla, as in the Viverrina, or rather more forwards, as in the Hyanida. The artery may enter the cranial cavity through au aperture concealed, or almost concealed, beneath the anterior end of the auditory bulla, as generally in the Viverrina ; or it may enter through a very conspicuous foramen anterior to and within the bulla, as in the Herpestina and Galidictina. This foramen notches the sphenoid very deeply, so much as to seem sometimes even to perforate it. The condyloid foramen may be exposed or concealed ; and there may be considerable variation in this respect in different individuals of the same species. The palatine foramina may be in the posterior third, or well within the posterior half, of the palate, as always in the Felida; or they may be well within the anterior half of the palate, and often within its anterior third, as in all non-feline iEluroids. In Cryptoprocta they are very near the hinder end of the anterior half. In Cynogale they are very far forwards, only a little behind the incisive foramina. The upper alveolar border may be notched to receive the apex of a lower premolar, as in Hemigalea. The mandible may have its angle extending backwards almost or quite on a line with the inferior margin of the horizontal ramus, as in most Felida. It may, on the other hand, be very much bent up towards the condyle, as in Hyana. It may he singularly flattened beneath, as in Proteles. It may be very small, as in Arctictis, or everted (or bent in the opposite way to that in which it is bent in Marsupials), as in Suricata. The hinder portion of the inferior margin of the horizontal ramus may be very concave, as in many Viverrina. The coronoid process may be greatly elevated, yet inclining backwards towards its apex, as in the Felida. It may be elevated vertically, and more or less truncated at its summit, as in Prionodon. It may be raised but little, relatively, above the condyle, as in many Viverrina. The symphysis is generally moderate, but may be greatly prolonged, as in Galidictis, where its proportional length to that of the mandible, from the front of the canine to the hinder end of the last molar, is as 62*9 to 100. The alveolar border may be singularly everted towards its hinder end, as in Arctogale. |