PLATE I. 



Li i r\ I'DfJO. 



IflO. 1. OSTRBA LUOUBRI8 j.,.. 



1 a. Under valve attached to a piece of rock, and showing the inside, with the orasoalar impression. 



1 />. Outside view of an upper valve of same. 



1 0. Outside view of an under valve, showing (he scar of attachment, which is unusually small. 



1 d. Inside view of another specimen. 



FIG. 2. Osrniu rxuoKMis 1>)4 



•2(t. Inside view of an under valve. 

 '2 b. Outside of same 



2 c. Lateral view of same. 



FlG. '■). F.XOdVKA I'iiI.i:mi;ki,I„V ^A 



3a. Outside of under valve, from a wax cast taken in a mould left in the matrix. 



'■'> b. An internal easl of an under valve. 



:! 0. Side view of same. 



3d", An internal cast left in the rock, of the inside of the upper valve. 

 FlG. 4. A.NOMIA nitida iog 



1 a. View of an upper valve, with only a portion of the shell attached to the cast. 



1 b. An outline Bide view of the same. 



FlG. A Pl.K AIUI.A AlIKNAKIA ^(\ 



5 a. An internal cast of the under valve. 

 5 b. Outside of the upper valve. 

 •">'■. A side view of same. 



FlG. 6. Inoci'.ijamis FRAGIUfi j.>7 



FlG. 7. Cai-kotixa m counts taa 



7 a. A view of one of the valves. 



7 b. The two valves together. 



FlG. A Cvi'MMkui.y ? CRAS6A 128 



8 a. Outside of a right valve. 



8&. An internal cast of the same valve, showing the muscular and pallial impressions and a cast of the 



lunge. 

 8c. Hinge of the right valve. 

 8 <1. An anterior view. 



