48 
Fig. Z\.—LAMELLIBBANV1IIATM8. 
Fig. 81 : a, Pecten Poulsoni ; J, Ostrea larva ; e, Exogyra costata ; rf, Gryphata vwicula- 
rU; *, C. Pitcheri? ; y, Inoceramus problematicus ; Grammysia bisulcata ; -4, Orthonota 
undulata ; t, Pterinea (labella ; *, Microdon bellastriata. 
In the collection there are but few species represented below 
the Trenton, but there are many forms represented under that 
period ; see Case c, Sects. 3 and n. Under other epochs there 
are species represented in Case d, Sects. 8 and 10 ; Case e, Sect. 
