Watte. — Pleii of Necturxis. 



PLATE 2. 



Fig. 5. Diagram of plexus of both sides in a specimen bearing asymmetrical sa- 

 cral ribs on vertebrae 19 and 20. 



Fig. 6. Diagram of plexus of both sides of a specimen bearing asymmetrical sa- 

 cral ribs on vertebrae 18 and 19. 



Fig. 7. Diagram showing a bifurcate transverse process and sacral rib. 



Fig. 8. Diagram of sacrum of a specimen with a supernumerary sacral rib on one 

 side. 



