468 



DR. H. W. MARETT TIMS ON THE 



also would certainly belong to the Macrodont series and it has like- 

 wise ten cusps. The same increase in the number of cusps may 

 be seen in the lower carnassial teeth in members from opposite 

 ends of the series. I would also draw attention to the increase in 

 size of the external cingulum in passing up the series ; indeed, 

 in O. anthus it forms a projection at the antero-external angle of 

 the tooth, nearly half the height of the Paracone itself. This I 

 regard as an important point, as I have already shown that cusps 

 aie formed on it in Otocyon. The same condition is also to be 

 seen in some of tlie InsectiA^ora — a condition which, I believe, 

 should necessitate reconsideration of the interpretation of the 

 cusps in some of tho^^e forms which are regarded as having 

 typically tritubercular teeth. 



The same increase in the number of cusps may be noted 

 in the Alopecoid series. In fig. 8 are sho.\n the biting- 



Fig. 8. 



pr- 



pci 



pa. 



pr 



pet 



pa. 



The biting-surface of the First Right Upper Molar tooth of— A. Canis 

 littoralis ; B. C. niloticus ; C. C. lagopus. (Alopecoid Series.) 



surfaces of the first right upper molar of C. littoralis (C. virgi- 

 manus, Mivart) (88. 11. 25. 2), C. nilo'icus (56. 3. 12. 14), and 

 of C. lagopus (88. 2. 20. 12). C. littoralis is one of the lower 

 Microdont Alopecoid dog.'', while the two latter belong to the 

 Macrodont series, and in these more cusps are present than in 

 C. littoralis. 



This conclusion has been arrived at after a very careful study 

 of the large number of skulls of the Cauidse preserved in the 

 British jVluseum. In some cases the teeth were too worn to 

 aftbrd very reliable information ; I was therefore led to select 



