36 Annals of the Carnegie Museum. 



antero-posterior diameter than in P. emarginatum and D. elatumJ 

 Judging from the type (lower jaw) of Protitanotherium superhum 

 Osborn, recently described,'" that species also has the same proportion 

 of the molar-premolar series as the two latter, while Telmatherium? 

 altidens of the same publication has a longer premolar series and more 

 nearly agrees with the present genus. 



Measurements. 



No. 2859. No. 2858, 

 Mm. Mm. 



Length of superior incisor series 34 33 



1~. Antero-posterior diameter 11 ii 



1-. Transverse diameter 10 10 



I-. Antero-posterior diameter 12 12 



I-. Transverse diameter ; 12 12 



I~. Antero-posterior diameter 15 15 



I-. Transverse diameter 14 14 



Canine. Antero-posterior diameter at tiie base 19 20 



Canine. Transverse diameter at the base 18 18 



Length of molar-premolar series 246 



Length of superior premolar series loi 



P-. Antero-posterior diameter 19 



P-. Transverse diameter 12 



P-. Antero-posterior diameter 22 23 



P-. Transverse diameter 25 26 



P^. Antero-posterior diameter 30 



P-. Transverse diameter 31 



P-. Antero-posterior diameter 33 31 



P-. Transverse diameter 38 36 



Extent of superior molar series 146" 



M-. Antero-posterior diameter 38 



M-. Transverse diameter 45 



M-. Antero-posterior diameter 52 



M-. Transverse diameter 54 



M-. Antero-posterior diameter 57 



M-. Transverse diameter 51 



I3 . Antero-posterior diameter 14 



I;;. Transverse diameter 12 



Canine. Antero-posterior diameter, approximately 17 



Transverse diameter, approximately 14 



^ In remeasuring the molar series of Prof. Marsh's type of Diplacodon elatum it 

 would seem that he was in error in regard to the measurement, which should read 

 167 instead of 152 mm. 



1" Osborn, Henry F., "New and Little Known Titanotheres from the Eocene 

 and Oligocene," Bull. Amer. Mus., Vol. XXIV, 1908, p. 615. 



11 Professor Marsh's measurement of the molar series of the type of D. elatutn 

 is an error. 



