XVI CONTENTS. 



CHAPTER XXIII. 



General characters of the Lamellibranchiata Shell of the Lamelli- 

 branchs General distribution of the Lamellibranchiata in time 

 Ostreidae Aviculidae Mytilidae Arcadae Trigoniadse 

 Unionidse Chamidae Hippuritidae Tridacnidae Cardiadae 

 Lucinidae Cycladidae Cyprinidse Veneridae Mactridae 

 Tellinidae Solenidae Myacidae Anatinidae Gastrochsenidaa 

 Pholadidae, ...... . 464-511 



