105 



'"'1 I 111 Ulli livlos.-d c ni .. .:' .! .::i;:,:il .m.l .HiMhT tUtM ipi I'M -', I 



(Ana Bati). The niunbcr of nerve-outlets in the coalesced anterior portion 

 of the column indicates that of the vertebrae which form it. The parapophysefl 

 of the anterior vertebrae form articular surfaces for the two condylcs of the 

 occiput. H**teria*. 



505. The vertebral column of a young Skate (Raia Bali*). Hunterian. 



506. A similar specimen. IIuntcria*. 



507. A similar specimen. JInnteria*. 



In each of these may be noticed the great breadth of the neural and hrmal spinen, which 

 are fewer in number than the bodies of the rertebne themselves. 



508. A vertebral column of a young Skate (Raia Balis). 



A vertical section has been removed from the connate anterior portion, showing the central 

 element modified or metamorphosed as in the cranium of higher vertebrate animals into a 

 flattened bony plate, connate with similarly flattened and expanded walls of the neural canal. 



Presented by Prof. Oven, F.R.S. 



509. The vertebral column of a young Skate. 



510. A similar specimen. 



511. A longitudinal section of the anterior vertebrae of a Skate (Raia Bali*). 



The anterior centrums hare coalesced into a flattened plate, continuous with the similarly 

 uniform walls of the neural canal. The section of the posterior vertebrae shows the ossified 

 terminal plates united chiefly by longitudinal plates with interspaces that were filled with 

 cartilage,. The neurapophyses are short and directly perforated by the motor roots of the 

 nerves : the interaeurapophyses are larger and are perforated by the sensory roots. The 

 parapophyses are. beut and interlocked, the anterior angle of one fitting into a posterior 

 notch of the vertebra in advance. 



Pretexted by Prof. Owen, F.R.ff. 



512. A portion of the abdominal and caudal vertebra? of a Skate (Raia Halt*), 

 showing the bending-down of the parapophyses in the first and second caudal 

 vertebrae to form the haemal canal. The neurapophyaes (*)> the interneur- 

 apophyses (0, and the neural spines (), are well shown in this 



Prncnied by Prof. Owen, F.R.S. 



