712 de. e. lonnberg ox the [June 19, 



sharpness, stoutness, and prominence of the three principal costse 

 on their outer surface, and the small development of the two 

 secondary ones." This is quite right, but it caDnot be regarded as 

 proving any close ovine affinity, as it is a primitive feature shared 

 by a large number of Antelopes. In the next line (/. c.) Dawkins 

 asserts of the upper true molars, as sooie authors (Bichardson, 

 7. c. p. 71 &c.) have done before him : " On the internal aspect 

 there is no accessory column ; " and he lays much weight on this. 

 About five years earlier, however, the keen observer Biitimeyer 

 had (I.e. p. 91 footnote) stated the normal presence of such 

 accessory columns, although they are small. On the material I 

 have received from the Katborst Expedition to East Greenland, 

 1 am able to verify Biitimeyer's observations (fig. 7). These facts, 

 in addition to the above statement concerning the milk-teeth, indi- 

 cate that there is a remarkable difference in this respect between 

 the dentition of the Musk-ox and that of the Sheep, instead of the 

 presumed likeness. The " small accessory valley at the inner 

 interspace between the two principal ones," as it is described 

 by Dawkins (I. c. p. 8), is present in the upper true molars of 

 Ovibos, which in this respect resembles Bovida>, as that author has 

 stated. The same valley is also found in Nemorhcedus, Hupicapra, 

 and in Bubaline, Hippotragine 1 , and Tragelaphine 2 Antelopes, but 

 not in Antilqpe, Gazella, &c. In Sheep and Goats this " accessory 

 valley" seems to be less constantly developed. Ovibos differs 

 therefore with regard to its molars more from the Caprina and 

 Antilopina than from the Bupieaprina. Bubalidina, Hippotragina, 

 and Bovina. With the first mentioned of these latter groups it has 

 the " accessory valley " in common, and with the others also the 

 accessory column. The question now is to decide how much can 

 be regarded as parallel and how much as affinity. This decision 

 is again dependent upon what may be the origin of the accessory 

 column. Biitimeyer seems inclined to make a sharp difference 

 between accessory columns and basal tubercles 3 . The former he 

 thinks are derived from the isolated inner column of the Anoplo- 

 iherium tooth ; the latter are " blosse Ausbildungen des unter 

 Hufthieren so allgemein verbreiteten Basalwulstes." As " ac- 

 cessory columns" he counts only those between the two main lobes 

 of the inner side of the upper molars ; but as " basal tubercles " 

 are regarded not only accessory elements found at other places on 

 the upper molars, but also all accessory tubercles and columns on 

 the mandibular molars, even if they look exactly like the accessory 

 columns, recognized elements of the upper molars and just as much 

 developed. Such a division seems, however, less easy to carry out 

 in a quite satisfactory manner. At the same time that Biitimeyer 

 calls the accessory elements of the mandibular molars in Bos basal 

 tubercles, he admits himself that a basal tubercle can be developed 

 to something in shape and structure absolutely like an accessory 



1 Cf. Rutimeyer, Gescb. d. Rind. tab. i. fig. 11. 



2 Cf. Flower and Lydekker : ' Mammals, living and extinct.' 



3 Gescb. d. Rind. pp. 78-79. 



