FOSSIL CHIM.€ROIDS. 



137 



Figs. 1 16-120. — Association of dental plates of early CKimaeroids. 



1 16, Ptyctodus, restored dentition, after specimens in Museum of Comparative Zoology, Cambridge. Mass. 



117, Palaeomylus, after specimens in Newberry collection, American Museum of Natural History. 



I 18. Rhynchodus, after specimen in Newberry collection. American Museum of Natural History. 



I 19, Myriacanthus, after specimens in the British Museum, and in the Jermyn Street collection ; the triloral areas of the two anterior 



pairs of plates m the upper jaw are shown in detail in fig, 1 19 A. 

 120, Squaloraja, after specimens in the British Museum, and in the Museum of Compaiative Zoology, Cambridge, Mass. 



