H. L. Hawkins del 



Fig. 1. Peristome of P. ornatus, external view, x c. 3. 



>. 2 - >> »i n internal view. x c. 3. Coll. Univ. Coll., 



Reading, Geol. Dept., No. 924. The figure is partly restored, several 

 of the processes having been broken during development. 



,, 3. Oral aspect of a pair of processes, x c. 6. 



>, 4. ,, ,, an interradial " ridge " . X c. 12. 



