6 4 



THE FORAM1NIFERA 



and disposition of the chambers are well displayed. In the 



B 



FIG. S. 



Polystomella crispa. A, the megalospheric, B, the microspheric forms, decalcified, b, the 

 central chambers of the latter more highly magnified. The canal system is omitted in these 

 figures for the sake of clearness, r, retral processes ; st, communications between the chambers. 



megalospheric form the retral processes characteristic of the genus 

 are present in the chamber following the megalosphere (Figs. 8, A, 



