R. S. Lull — New Tertiary Artiodactyls. 



101 



Scott's specimen had no trace of any lower jaws; 

 Douglass, on the other hand, figures several pertaining 

 to Dromomeryx americanus , borealis, and madisonius. 

 His restoration of the skull of D. borealis 7 shows a 'jaw 

 very different from that of Aletomeryx at the anterior 

 end, as it is much more slender and lacks the graceful 

 downward curve of the upper margin. It is possible that 

 the figure may be somewhat in error, especially as the 

 mental foramen is omitted. 



The posterior portion of the jaw of D. borealis is not 

 preserved. The condyle in Aletomeryx shows a saddle- 

 shaped surface comparable to that of Antilocapra. 



Mandibular dimensions appear below. 



Aletomeryx 



10754 

 Unworn 



10763 

 Mt 'd. sp 'm. 



10762 



Length of ramus 



Depth at P 2 



Depth at M x 



Depth at M 3 , outside 



Length of molar -premolar ser. 



Length of premolars 



Length of molars 



ESL male 

 milk 

 m. 



Length of ramus -2150 



Depth at P 2 0230 



Depth at M x -0324 



Depth at M 3 > outside -0337 



Length of molar -premolar ser -0775 



Length of premolars -0282 



Length of molars . -0490 



m. 



m. 



m. 



•1330 



•1340 



•1327 



•0130 



•0149 



•0137 



•0165 



•0160 



•0170 



•0218 



• 0240 



•0214 



•0630 



•0640 



•0610 



•0210 



•0223 



•0200 



•0425 



•0426 



■0410 



Antilocapra 



ESL 

 180 female 



female milk 



m. 

 •2130 

 •0215 

 •0240 

 •0355 

 •0750 

 •0240 

 •0490 



m. 

 •1960 

 •0200 

 •0324 

 •0345 

 •0800 

 •0300 

 •0500 



10761 

 Very 

 old 

 m. 

 •1250 

 •0128 

 •0144 

 •0180 

 •0586 

 •0183 

 •0377 



Eatio 



10762 



and 180 



1-60 

 1-49 

 1-41 

 1-66 

 1-23 

 1-20 

 1-20 



Av. 1-39 



Teeth (figs. 7, 8). — The dental formula of Aletomeryx is 

 If* Vf, Pf, Mf, agreeing therein with the Antilocapridae, 

 Girafndse, Bovidag, and with all Cervidse in which the upper 

 canine is lacking. The incisiform lower canine is pres- 

 ent as in the above families. 



The first premolars are of course lacking in each jaw, 

 but the remaining premolars and molars form a compact 

 row in which the teeth show a slight tendency to overlap 



7 Op. cit., pi. LIX. 



