28 ODONTORNITHES. 



as commencing' upon the seventh. A similar structure is seen in the cor- 

 responding vertebra of the Loon. In Bhea, these tubercles suddenly appear 

 upon the sixth vertebra. The elongated tubercles in which the lateral 

 ridges terminate posteriorly are smaller and less conspicuous in the seventh 

 than in the sixth vertebra. The articular surfaces are larger, and some- 

 what more expanded below. 



The pre-zygapophyses are nearly flat, being only slightly convex. 

 The post-zygapophyses are slightly concave, especially near the internal 

 angle. The base of the neural spine extends over nearly the whole 

 length of the neural arch, but was probably shorter antero-posteriorly 

 above, than in the sixth vertebra. The lateral foramen is slightly larger, 

 and the diapophysis upon its outer wall is greater, more produced down- 

 ward and forward, and farther from the pre-zygapophysis than in the 

 sixth vertebra. A short ridge rising into a crest over the post-zygapophysis 

 is developed in one specimen (number 1208). The posterior outline of 

 the neural arch is notched behind at the termination of the neural spine, 

 as in the preceding vertebrae, but less deeply. The pleurapophyses are 

 longer than in the sixth vertebra. 



The measurements of two specimens of the seventh cervical vertebra 

 of Hesperomis regalis are given below : 



Measurements of Seventh Vertebra. (No. 1206.) 



Length of centrum, 32.0 mm 



Transverse diameters of anterior articulation of centrum, . . 10.0-16.0 



Vertical diameters of anterior articulation of centrum,.. 7.0-10.0 



Transverse diameter of vertebra, across pre-zygaj>ophyses, 25.0 



Transverse diameter of vertebra, across post-zygapophyses, - 2*7.0 



Diameters of post-zygapophyses, 8.0-11.0 



Total length of pleurapophysis, . ... 31.0 



Length of free portion of pleurapophysis, 23.0 



Measurements. (No. 1207.) 

 Length of centrum, 32.0 mm 



Least transverse diameter of base of centrum, 8.5 



Transverse diameters of anterior articulation of centrum, 11.0-16.0 



Vertical diameters of anterior articulation of centrum, 6.5-10.0 



Transverse diameters of posterior articulation of centrum, ... 1 1.0-15.5 



Vertical diameters of posterior articulation of centrum, 6.5-10.0 



Transverse diameter of vertebra, across pre-zygapophyses, 26.5 



