HOLLAND AND PETERSON: OSTEOLOGY OF THE CHALICOTHEROIDEA. 263 
is located the vertebrarterial canal, which is large and oval in cross-section. The 
outward extremity of the transverse processes is enlarged, somewhat truncate, 
and rolled downward like a scroll with the anterior tubercle pointing forward 
and downward and the heavier posterior tubercle pointing outward and upward. 
Fia.31. Third cervical of M. petersoni (1703A). 1, lateral view; Fia. 32. Cross-section of third cervical 
2, posterior view. Xi. vertebra of M. elatus (No. 1604). 4. 
The lower margin of the vertebrarterial canal is continuous with a deep fossa on 
the upper side of the lower lamina of the transverse process, which is continued 
backward as an upwardly bent scroll-shaped projection until it fuses with the 
margin of the posterior articulating face of the centrum about its middle. A 
cross-section of the bone is given in Figure 32. 
M®&aAsuREMENTS oF THIRD CERVICAL VERTEBRA. : 
No. 1604, 
Greatest length from front margin of prezygapophyses to hind margin below between perpendiculars. 190 
Heeb tatomoprolneuraluspinerarur aneeen ore crt oye! Lohan) Saye ame eee i Lees vechlamer cette Salers 155 
enothvolgcentramealongatneumderisuriacesnias ey yee ro ceed ee en teres alee ee ees 165 
ANMIGOAOOSMMSAOE CHATTACE OF [SONGS 85 og ood oo co eee a eee mac coue cok eaten cor a Ceca eRe eatin 80 
Diametersmeasuredeackossmaceror prezyeapophySesmmry anaes iste iels ete ase at) ys 138 
Distance between articulating faces of prezygapophyses above.........-......+---eeee reece ee 25 
Diametersmeasuredyackossace Ol posizyeapopysese =e aria ae eid ae se ee oe ol 152 
Distance between articulating faces of postaygapophyses in front........................-.005- 40 
Distance between articulating faces of postzygapophyses behind............................... 26 
Diameter across anterior extremities of transverse processeS............-.. 0200 e cece ee eee eee ee 112 
Diameter across posterior extremities of transverse processes... .........02. 00000 e eee eee eee 165 
Transverse diameter of articular faces of prezygapophyses..............2--002 2002s eee eee eee 60 
Supero-inferior diameter of articular faces of prezygapophyses................00000-0-0- 22-220 50 
Transverse diameter of articular faces of postzygapophyses................----..-----.00---e- 60 
Supero-inferior diameter of articular faces of postzygapophyses..............-....----..22e00e 65 
Wenigall clenmeusr of ieuirll GLA: co co scoouedcsandee nae ep yOu eee > UUcms a yo smo mrcape 35 
TTiAMEVERS® Glanncier OF mewmall C2MEIl., 505s cakcswsoeobene sue bocebouoodseoaoo ae mueommdcds See oe 30 
