PLATE XXXI. 



PAGE 



Fig. 87. Mytilus quadratus. Natural size. 191 



Fig. 88. Modiola MAJOE. A rather small specimen. 191 



Fig. 89. Meleagrina antiqua. Natural size. 192 



Fig. 90. Inoceramus Elliotii. A cast. 193 

 90 a. Form of tlie ribs from the impressions in the matrix. 



