438 



MESOZOIC TIME. 

 Figs. 775-779. 



Brachiopods and Lamellibranchs, of the Lias. — Figs. 775, 776, Leptaena Moorei (X7); 776 a, 

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



Fiffs. 780-785. 



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

 tata ; 783, Trigonia clavellata ; 784, Astarte minima ; 785, Diceras arietina. 



