2 



Peterson : A Small Titanothere from the Uinta Beds. 55 



poitions found generally in the Eocene Titanotheres. The deciduous 

 cheek-teeth are three in number and theii increase from first to last 

 is unusually rapid. The crowns of the first and second deciduous 

 cheek-teeth are broken ofT, but the gi eater part of the last tooth is 

 preserved. The piincipal feature of this tooth is the piesence of two 

 large internal tubercles which aie conical in 

 shape and covered with a heavy coating of 

 enamel. The antero-external angle of the 

 tooth is extensively developed, so that the 

 antero-posterior diameter is considerably 

 greater than the transverse. M- is just ap- „ 



, , , 1111 11 ^l<^- 2. H eleroiilanops 



pearing through the alveolar bordei and has ^^^^„^ Peterson. (Type, 

 been freed for the purpose of study. The No. 2909.) x |. 

 proto- and hypocones usually found in the i. Deciduous dentition 



Titanotheres aie pi esent, and well developed, ^^'^ permanent M ; 2, 

 while the external face of the ectoloph is less " ^' 



concave fore-and-aft and the median vertical ridge has a somewhat 

 greater forward projection than is generally the case in the Titano- 

 theres. The germ of M- is quite well advanced, while that of M- has 

 apparently not yet been formed. 



The first lower cheek-tooth is seen buried in the ramus, but is not 

 represented in the illustrations. D-^- and D are injured while My is 

 well preserved. Its crown is like that of the typical Eocene Titano- 

 theres and needs no description. My is well advanced towards 

 maturity while M-g- is not yet indicated. 



Measurements. 



Mm. 



Total length of skull from canine to and including the occipital condyle. . . . 142 



Transverse diameter of skull at the parietal region 46 



Greatest transverse diameters of frontals 54 



Length of alveolar border, canine to and including M~ 67 



Length of deciduous cheek dentition 38 



Antero-posterior diameter of D- 21 



Transverse diameter of D- 15 



Antero-posterior diameter of M- 24 



Transverse diameter of M-, approximately 20 



Antero-posterior diameter of My 25 



Transverse diameter of M j 12 



The axial and appendicular parts rest on the concretionary sand- 

 stone block in the position in which they were found imbedded. 



