40 ODOXTORXITIIES. 



Measurements of Fifteenth Vertebra. (No. 1476.) 



Length of centrum,. 22.0 mm 



Transverse diameter of anterior articulation of centrum, ". 22.0 



Vertical diameters of anterior articulation of centrum, . 6.0- 9.0 



Transverse diameters of posterior articulation of centrum, 14.0-19.5 



Vertical diameters of posterior articulation of centrum, 8.0-14.0 



Transverse diameter of vertebra, across pre-zygapophyses, - . - . 36.0 



Transverse diameter of vertebra, across parapophyses, . ... 30.5 



Diameters of pre-zygapophyses, 10.0-10.5 



Length of floor of neural canal, . . 23.0 



Length of roof of neural canal, _ ... 20.5 



Transverse diameter of neural canal, at anterior opening, _. 9.0 



Vertical diameter of neural canal, at anterior opening, ._ 7.5 



Transverse diameter of neural canal, at posterior opening, 8.0 



Vertical diameter of neural canal, at posterior opening, 8.0 



Diameters of articulation for head of rib, 6.0- 5.0 



Measurements. (No. 1477.) 



Length of centrum, 22.0 mm 



Transverse diameters of anterior articulation of centrum, 14.5-22.0 



Vertical diameters of anterior articulation of centrum, 6.0- 7.5 



Transverse diameters of posterior articulation of centrum, 15.0-22.5 



Vertical diameters of posterior articulation of centrum, . . 8.0-14.5 



Transverse diameter of vertebra, across pre-zygapophyses, 34.0 



Transverse diameter of vertebra, across post-zygapophyses, .. 32.5 



Diameters of pre-zygapophyses, . . 9.0-13.0 



Diameters of post-zygapophyses, 10.5-14.0 



Length of floor of neural canal, 21.0 



Length of roof of neural canal, 20.0 



Transverse diameter of neural canal, at anterior opening, 10.0 



Vertical diameter of neural canal, at anterior opening, 8.0 



Length of hypapophysis,. 15.0 



Diameters of articulation for head of lib, 7.0- 7.5 



Distance between extremities of anterior and posterior zygapophyses, 37.5 



The Sixteenth Veetebea. (Plate IV, figure 7.) 

 The sixteenth vertebra differs considerably from the fifteenth, and 

 begins to assume the distinctive features of the dorsal vertebrae. It is 

 shorter than the fifteenth, and is the shortest vertebra between the atlas 

 and the sacrum. The centrum is excavated at the sides, and its articular 

 faces are laterally expanded, but of little vertical extent. A strong hypa- 

 pophysis descends from the inferior surface, rather more vertically than in 

 the preceding vertebra. The articular face for the head of the second rib 



