OCR Text |
Show 14 MR. A. H. GARROD ON THE [Jail. 2, being filled up by the appearance, superficially, of portions of the nasal turbinal. This is also the case in Cervus pudu and C. columbianus. In C. leucurus the nasal processes of the praemaxillae are also very short, and they therefore do not join the nasal bones; nor do they in C. campestris, nor, generally, in C. rufus, and only just in C. virginianus. They do join the nasals in C. leucotis and C. antisiensis. In Alces machlis, on account of the extreme shortness of the nasal bones, the premaxillary processes do not meet them ; but in all the Old-World Cervidae the line of junction of the two is considerable, except in Elaphodus cephalophus and Cervulus reevesi. In all the American Cervidae and in the Reindeer the floor of the posterior osseous nares is prolonged backwards more than in their Old- World allies, from the extension backwards of the palatine plates of the palatal bones. In Cervulus there is a tendency to this condition, but not in any other Old-World genus. In his invaluable paper1 " O n the Evidences of Affinity afforded by the Skull in the Ungulate Mammalia," Mr. H. N. Turner remarks:-"I have noticed that in the Moschidae [Hyomoschus, Tragulus, and Moschus'] the styloid process [tympano-hyal] becomes free almost immediately at the base of the auditory process, while in the Bovidae, or Cavicorn Ruminants, it is enclosed, more or less completely, for some distance in the downward and forward direction." And in all the Cavicornia which I have examined, the tympano-hyal bone is situated on the outer side of the petrosal; whilst in many of the Cervidae it is posterior, between the petrosal of the temporal and the paramastoid of the occipital bone. In Cervus porcinus and Axis maculata, however, the expanded auditory bulla insinuates itself from the inner side, between the tympano-hyal and the paroccipital process, as in the Cavicornia. Neither in any of the American Cervidae, except C. leucotis, nor in Rangifer tarandus, Alces machlis, Capreolus caprea, Cervus dama, nor in the genera Cervulus and Elaphodus, does it do so. In the other Deer (Elaphine, Rusine, and their allies), including Elaphurus davidianus and C. leucotis, there is a small process of the petrosal, incomparably less than in the Cavicornia, which, from the inner side, partially or just removes the tympano-hyal from the paroccipital (as seen without damage to the skull). This is well marked in Hydropotes inermis; and Moschus moschiferus is peculiar, in that from the outer side a process is sent inwards to join the other, and so completely to encircle the tympano-hyal with a ring of bone in a very suspiciously Cavicorn manner. The Giraffe, in this respect, much resembles Moschus. It is worthy of note that in Cervus antisiensis the median incisors are not triangular, in which respect it agrees with Rangifer and Moschus and differs from the Cervidae generally. In C. leucotis they are so. In C.pudu, as in Moschus, the Giraffe, and many Cavicornia, there is only one submental foramen on each side-not two, as in by far the majority of the Deer. The peculiar way in which, on each side, the palatal surface of 1 P. Z. S. 1849, p. 152. |