TABLE OF CONTENTS. 



PAGE 

 Preface v 



Systematic list of species ......... ix 



CORBICULAD^E ........... 1 



CORBICULA ............ 2 



Recent species .......... 3 



Fossil species .......... 3 



BATISSA . 9 



VELORITA . . . . . . . . . . .10 



CYRENA 12 



Cyrena . . 12 



Anomalous species ......... 27 



SPHJERICM ............ 32 



Recent species .......... 33 



Fossil species .58 



PISIPIUM ............ 59 



Recent species 61 



Fossil species .......... 73 



Appendix 75 



Alphabetical index . .77 



(Tii) 



