PLATE L—Continued. 
Fenestella erectipora. 
Page 118. 
Fig. 15. A portion of the non-celluliferous face enlarged, showing the appearance and comparative size 
of the branches and dissepiments. (X 5.) 
Fig. 17. A portion of the celluliferous face of the frond with the carinse broken away, showing the form 
and arrangement of the cell apertures. (X 6.) 
Upper Helderberg group. Ontario, Canada. 
Fenestella (Reteporina) rhombifera. 
Page 119. 
Fig. 18. A portion of the non-celluliferous face of a frond which is much worn or macerated. The four 
branches on the left of the figure are so much worn that the bases of the cells are exposed to 
view ; the remaining branches are less worn, but the surface characters are obsolete. (X 6.) 
Fig. 19. A portion of the non-celluliferous face of another frond, showing the branches well preserved 
and anastomosing, with a prominent node at the center of each junction. The celluliferous 
face in a perfect condition has not been observed, so that it is impossible to say with certainty 
to what subgenus it belongs, but probably to Reteporina. (X 6.) 
• Upper Helderberg group. Le Roy, Genesee county, N. Y. 
/ 
