714 dr. e. losnbebg ox THE [June 10, 



Examples proving such a statement may be found in sufficient 

 number, but I think that offered by the genus Cephalophus is 

 among the best. 



About this genus Sclater and Thomas say in ' The Book of 

 Antelopes' (p. 121): "Upper molar teeth short and broad; in 

 the larger species with an additional column on the inner side ; " 

 and Riitimeyer ' speaks of " Spuren von Basalsaiilchen." In the 

 small species of Cephalophus accessory elements are more or less 

 comparatively wanting. In a skull of C. melanorheus Gray, from 

 the Cameroons, I failed to find any accessory elements except on 

 the hindmost milk-premolar. Iu the skull of the medium-sized 

 C. dorsalis Gray, subsp. castaneus O. Thomas, the accessory 

 elements are well developed, not only as tubercles, between the 

 lobes on the inner side of all upper true molars. In the latter the 

 following condition is found. On the hindmost upper molar a 

 single tubercle is seen in connection with the aaterior lobe of the 

 inner side. On the middle and foremost upper molars, two 

 accessory elements are found close to each o;her between the 

 inner lobes and belonging one to either of them ; thus anterior 

 as well as posterior accessory elements are present. On the 

 outer side of the middle and hindmost upper molars a similar 

 tubercle is developed from the posterior lobes, and all mandibular 

 molars carry such a tubercle on the outer side of the posterior 

 lobes. In the largest species, Cephalojyhus sylvicultrix (Afzelius) 2 , 

 the accessory elements are present on the inner side of the upper 

 molars, and arranged in such a manner that those in the foremost 

 and middle molars belong to the posterior lobes, but in the hindmost 

 molar originate from the anterior lobe. In the mandibular molars 

 of the same species, accessory elements are found between the 

 lobes of the outer side. But in this species the accessory elements 

 have been modified into high columns, especially on the upper 

 molars, in correspondence with the development of the molars to 

 the hvpselodont type. I do not think that it can be regarded as 

 hazardous to draw the conclusion from this, that all these acces- 

 sory elements of the molars are of the same morphological rank 

 although differently developed in various species, depending upon 

 the varying conditions of life and the adaptation to the same. But 

 if this statement is accepted, as I hope it will be, there is no need 

 to postulate any close kinship between such Cavicornia as are 

 provided with accessory columns to the molars. They need only 

 to be derived from more primitive forms which have been able to 

 develop accessory tubercles, out of which the columns have been 

 independently formed with the development of a hypselodont 

 dentition. Consequently the presence of the small accessory 

 columns of Ovibos need not suggest any relationship between this 



1 ' Die Rinder der Tertiar-Epoche, 'p. 38. 



- This species does not seem to hare to have been recorded from the 

 Cameroons before. Mr. Linell. a Swedish planter residing at Cape Debundsoha. 

 has sent home the flat skin and the skull of a young, but probably full-grown, 

 female of this species. 



