Genera of the I^orth American Palaeozoic Bryozoa. 463 



we observe a thick portion of the endocyst projecting into the 

 cavity. This is the rudiment of the future polyp. Within this 



Fig. 26. Paludicella Ehrenbergi, showing development of bud (after Allsian). 



when viewed from the front, may be seen an oval ring, which 

 develops into the lophophore, e. This ring is at first a mere 



