EXPLANATION OF PLATE B. 



Fig. 1. Mesodon barnesi, sp. nov. ; left side view of fish, nearly one-half natural 

 size. Portland Stone; Portland, eth., mesethmoid ; occ., occipital 

 crest ; orb., orbit ; plv., pelvic fins and supports ; r. spl., right splenial ; 

 v., vomer. [Collection of F. J. Barnes, Esq.] 



Fig. 2. Ditto ; right splenial dentition of same specimen. 

 Fig. 3. Ditto ; inner face of two scales of same specimen. 



Fig. 4. Ditto ; impression of outer face of scales of same specimen, showing 

 ornamental tubercles. 



Fig. 5. Mesodon damoni, A. S. Woodw. ; left splenial with dentition. Portland 

 Stone ; Portland. [British Museum, no. P. 7,509.] 



Fig. 6. Mesodon granulatus (Miinster) ; right splenial with dentition. Kim- 

 meridge Clay, Weymouth. [British Museum, no. P. 3,788 d.~] 



Figs. 2-6 nat. size. 



