EXPLANATION OF PLATE XIL 



Bones o£ Piotostega gigas, one- 1 hi id natural size, except Fig. 1, which is oue-balf nature. 



Fig. 1. Neural arch of ? cervical vertebra, from above. 



2. Left humerus. 

 Figs. 3-4. Metapodial bones. 

 Fig. 5. Scapulo-procoracoid of the rigbf- side. 



t'. Coracoid of the right side. 

 Figs. 7-9. Phalanges. 

 Fig. 10. Normal lateral marginal bone, from below. 



11. Vertebral ? nuchal bone, from above. 



V2. Marginal bone with two lamina;: a, from without ; //, from the proximal or inner margin. 



13. Long anterior marginal bone. 



