438 



MESOZOld TIME. 



Figs. 775-779. 



Brachiopods and Lamellibranchs, of the Lias —Figs. 775, 776, Leptsena Moorei (x7); 776 a, 

 same, natural size; 777, Spirifer Walcotti ; 778, Lima (Plagiostoma) gigantea (X%)i 779, 

 Gryphaea incurva (X%). 



Lamellibranchs comprised several new genera. Gryphcea (Figs. 

 779, 782), of the Oyster family, having an incurved beak, commenced 

 in the Lias, and was a characteristic kind. 



Figs. 780-785 



Lamellibranchs, of Oolyte. — Fig. 780, Ostrea Marshii ; 781, Exogyra yirgula ; 782, Gryphaea dila 

 tata ; 783, Trigonia clavellata ; 784, Astarte minima : ^85j Diceras arietina. 



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