OCR Text |
Show 716 DR. E. LONNBERG ON THE [June 19, widely separated from the nasals in Budorcas, and even the raaxil-laries only touch them with a very short suture. The same is also the case with the upper anterior corner of the lachrymal bones. But, on the other hand, the nasals of Budorcas are comparatively more deeply sunk in between the frontals than in any other form. This can be concluded from the fact that the lateral suture between nasals and frontals measures about 7 cm. on each side, the posterior not reckoned. It is thus evident that the nasal portion of the skull of Budorcas ha3 undergone such a transformation and specialization, that it can very well be used for comparison in determining the systematic position of this animal. The lachrymal bone of Budorcas is anteriorly very high or broad, and resembles in its shape that of some species of Nemorhcedus \ If the orbital tube of Ovibos is abstracted, there is a certain likeness in this respect between these forms, but this bone varies considerably writhin the same genus (Nemorhcedus). The concavity of the lachrymal bone of Budorcas is very slight. The foramina incisiva are larger in Budorcas than in Ovibos, so that their length in the former is contained three times and a third in the distance from the anterior end of the intermaxillaries to the posterior end of the palatines, but in the latter a little more than four times 2. The intermaxUlce are shaped anteriorly as in Nemorhcedus and allied forms, and resemble the condition found in the Caprina, and are thus comparatively less pointed than in Ovibos. The crista masseterica of Budorcas nearly reaches the lachrymal bone in front of the orbit, as there is only an interspace of 2 or 3 m m . From its highest point in front of tbe orbit it descends steeply to the tuber maxillare which is situated above the first molar, but in Ovibos usually above tbe second. In Nemorhcedus, this is subjected to great variation depending upon the size of the anteorbital pit and lachrymal; if these are large the crista is low and extends to the first molar, but if the lachrymal bone is narrow the tuber maxillare is situated above the second molar. The palate of Budorcas is less concave than that of Ovibos, but the fold on the inner side between the two lobes of the molars is deeper in the former and there is, at least on the specimen at hand, no trace of accessory columns. The molars of the mandible are also rather similar, but the third or hindmost lobe of the third molar seems to be larger and better developed in Budorcas than in Ovibos. In the latter the lateral semilunar lobes are more broadly arcuate than in the former, in which the outline on the worn crown nearly forms an angle. The incisors of Budorcas are much broader and larger than those of Ovibos, and resemble those of Nemorhcedus and Haploceros. The anterior opening of the canalis alveolaris mandibulce lies in Budorcas distinctly behind the symphysis, as also seems to be the 1 Rupicapra, which is regarded a.s an allied genus, has rather narrow lachrymals, and so has Haploceros. 2 In Nemorhcedus as in Ovis, 3\ times. |