LEPUS CUNICULUS 



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simply a low ridge most marked anteriorly. At the front end are 

 two large articular facets for articulation with the occipital condyles 

 of the skull. The transverse process is a wide flat lamina grooved 

 on its posterior edge for the second spinal nerve. The rib is repre- 

 sented by a flat plate of bone joining the transverse process and 

 leaving a triangular aperture for the passage of the vertebral artery. 



Cc OF 1 



FIG. 88. Vertebrae of Lepus. 



I., Lumbar vertebra, side view ; II., lumbar vertebra, front end ; III., thoracic vertebra, side 

 view ; IV., atlas, dorsal view, slightly reduced; V., cervical vertebra, posterior end; VI., axis or 

 epistropheus, side view. 



A., anapophysis ; C., C'., facets for articulation with capitulum of rib ; Ce., centrum ; C.R., 

 cervical rib ; H., hypapophysis ; I., intervertebral notch ; L., lamina ; L.F., lateral surface for 

 articulatioVi with atlas; L.F'., facet for articulation with lateral surface of axis; M., metapo- 

 physis ; N.C., neural canal ; N.S., neural spine ; O., odontoid process ; O.F., articular surface on 

 odontoid process ; O.F'., articular facet for articulation with odontoid process ; P., prezygapo- 

 physis ; Pe., pedicle ; P.O., postzygapophysis ; T., facet for articulation with tuberculum of rib 

 T.P., transverse process ; V., vertebrarterial canal. 



This aperture, the vertebrarterial canal, passes upwards through a 

 foramen in the neural canal through which the artery enters and the 

 first spinal nerve leaves the canal. 



The second vertebra, the axis or epistropheus, has a broad flat 

 centrum produced anteriorly into a peg-like odontoid process, which 

 is really the main part of the centrum of the atlas that fuses with the 

 centrum of the axis during development. The neural spine forms a 

 large vertical spine that projects forward some way over the atlas. 

 The anterior end of the centrum bears two facets for articulation, 

 with corresponding surfaces in the first vertebra, and the posterior 

 end bears zygapophyses that are quite typical and have their facets 



