102 M. S. Lull — Netv Tertiary Artiodactyls. 



so that the total length of the series is less than the sum 

 of their individual dimensions. 



The premolars in each jaw show no tendency to become 

 molarif orm. A curious partial exception lies in skull No. 

 10749, in which the third left upper premolar (P 3 ) has 

 two inner and but one outer lobe, which, however, is dis- 

 proportionately long. The equivalent tooth on the right 

 side is normal. This is of course an abnormality, an 

 instance of meristic variation. The cheek teeth show a 



Fig. 7. Upper dentition, crown view and from without, of Aletomeryx. 

 Cat. No. 10760. Slightly more than natural size. 



'* s **«fe 



a^wJW 



Fig. 8. Lower dentition, crown view and from within, of Aletomeryx. 

 Cat, No. 10754. Natural size. 



slight tendency to become hypsodont, although not so 

 much so as in the prongbuck. Herein they differ appar- 

 ently from D. borealis, in which "the molars are very 

 brachyodont ' ' (Scott). 



P 2 is an elongated oval, somewhat irregular in external 

 outline, and consists largely of a single cusp, the proto- 

 cone, flanked anteriorly by a pronounced accessory cusp. 

 Internally the deuterocone is the merest rudiment, on a 

 well-developed but narrow cingulum, which is in marked 

 contrast to that of Dromomeryx, in which P 2 bears a well- 



