446 



Annals of the Carnegie Museum. 



Distance from anterior margin of orbit to supra- 



occipitals 170 mm. 285 mm. 156 mm. 



Antero-posterior diameter of orbit 45 mm. 67 mm. 50 mm. 



Infero-superior diameter of orbit 36 mm. 63 mm, 50 mm. 



Mandible. 



Greatest length of mandible including incisors... 2S0 mm. 446 mm. 254 mm. 



Greatest height of mandible including coronoid 



process 150 mm. 225 mm. 158 mm. 



Height of coronoid process 48 mm. 77 mm. 50 mm. 



Depth of ramus at m. 3 48 mm. 67 mm. 43 mm. 



Depth of ramus at pm. i 25 mm. 36 mm. 20 mm. 



Length of diastema between canine and pm. I... 17 mm. 30 mm. 



Length of pm. I antero-posteriorly 9 mm. 



Length of continuous molar-premolar series 104 mm. 155 mm. 73 mm. 



Length of diastema between pm. I and pm. 2 17 mm. 



Distance from canine to continuous molar-pre- 

 molar series 45 mm. no mm. 63 mm. 



Length of pm. 2 10 mm. 



Breadth of pm. 2 5 mm. 



Length of pm. 3 12 mm. 



Breadth of pm. 3 5 mm. 



Length of pm. 4 12 mm. 24 mm. 12 mm. 



Breadth of pm. 4 7 mm. 16 mm. 8 mm. 



Length of pm. i 18 mm. 32 mm. 15 mm. 



Breadth of pm. I lo mm. 28 mm. 13 mm. 



Length of pm. 2 23 mm. 44 mm. 18 mm. 



Breadth of pm. 2 14 mm. 26 mm. 15 mm. 



Lengthofpm. 3 31mm. 57mm. 30mm. 



Breadth of pm. 3 13 mm. 21mm. 15 mm. 



The Vertebral Fonni//a. — The vertebral formula in O. longipes ap- 

 pears to be as follows : Cervicals seven, dorsals twelve, lumbars seven, 

 sacrals four and caudals fourteen (?). 



In the type (No. 918), the cervical region and the sacrum is com- 

 plete ; there are six dorsals and four lumbars represented, but no cau- 

 dals. While the caudal region is conjectural the writer is firmly of 

 the opinion that in other respects the vertebral formula is correct, in 

 view of the fact that it agrees with that of the recent Tylopoda, and 

 was perhaps fully established in the Uinta representatives.^ A skele- 

 ton (No. 562) which is referred to the genus 0\ydactyIiis and has the 

 comjjlete cervical region, the five anterior dorsals, three or four of the 



** In BtiU. Am. Mus. Nat. Hist., Vol. X, p. 107, 1898, Wortman describes Proty- 

 lopiis pelersoni as having four sacrals, seven lumbars, and intimates that there are 

 twelve dorsals. 



