ANATOMY OF MEGAPTERA LONGIMANA. 



81 



PART III. continued. 



THE VERTEBRAL COLUMN continued. 



Page 

 Neural Arch and Canal. 



11. Lamina, . . . .81 



12. Pedicle, . . . .82 



13. Neural Canal, . . . ' 84 



Articular Processes. 



14. Great Anterior Articular 



Processes, . . .84 



15. Internal Anterior Articular 



Processes, . . .87 



16. Posterior Articular Processes, 89 



1 7. Homology and Adaptation of 



the Articular Processes, . 90 



Transverse Processes. 



18. General Remarks, . .91 



19. Dorsal Transverse Processes 



of Megaptera, , . .92 



20. Costal Fossae, 



21. Lumbo-Caudal Transverse 



Processes, 



22. General Survey of Transverse 



Processes in Megaptera, . 



23. Transverse Processes of B. 



musculus, in comparison, . 



24. Dorsal Region, . 



25. Lumbo-Caudal Region, 



Spinous Processes. 



95 



97 



98 



98 



100 



101 



26. Form (and on page 103), 



27. Length, Breadth, and Thick- 



ness, .... 102 



28. Direction, . . . .102 



29. Spinous Processes of B. 



musculus, in comparison, . ] 04 



NEURAL ARCH AND CANAL. 



11. THE LAMINA. The length of the lamina is remarkable 

 compared with that of B. musculus, but owing to its obliquity 

 (upwards and backwards) and greater thickness the canal is not 

 higher than in B. musculus. The obliquity of the lamina is 

 very slight on the 1st dorsal, increases on the 2nd, 3rd, and 4th, 

 is very marked on the 5th and back to the 1st lumbar; after 

 this it diminishes rapidly along the posterior half of the lumbar 

 region, so that at the 9th or 10th lumbar the lamina is not 

 longer than at the same place in B. musculus. At the last 

 dorsal the length of the lamina proper is about 2 inches, 

 breadth 4, thickness 1J. At the last lumbar the length is 

 1 inch. 



[In B. musculus the first three dorsal laminae are directed a little 

 forwards ; obliquity backwards begins on the 5th. The much less 

 length of the laminse, compared with Megaptera, is recognised on the 

 7th and 8th, as soon as the articular processes assume the definite 



H 



