Manchester Memoirs, Vol. lx. (191 6), No. % 



3i 



not impossible that the ridging of the brain case in front 

 of it indicates that other segments have recently fused 

 with the primary chondrocranium. In front of this 

 region the brain case gives rise to a powerful process 



C. 



G. 



H. 



menacia curta, (after Hussakof.) ; E., Phaneropleuron andersoni. 

 (No. L. 10867.) Dura Den, Fifeshire. (Rosebrae Beds); F., Sagenodus 

 incequalis, (No. L. 10904), Upper Coal Measures ; G., Ceratodus 

 forsleri, (after Goodrich); H., Ctenodus cristatus, (modified from 

 Smith Woodward), Middle Coal Measures. Reference letters as before. 



which articulates with the roof of the skull, mainly indeed 

 with the outer of the posterior row of three bones. Below 

 this is an excavation in the side of the skull wall, marked 

 off behind by a ridge which rises to the process and 



