PLATE XXX 

 PLEURODICTYUM LENTICULARE HALL (PAGES 423, 424) 



FIGURE 1. Outline of upper side of specimen with eight peripheral 

 calices. X 3. 



FIGURE 2. Upper side of symmetrical specimen; showing general 

 features of calices, mural pores in central corallite, and thickened epithe- 

 cal border. X 3. 



Lower Helderberg Group, Albany county, New York. 



