1 i.i r>.i/M'r 



PIvATE I^Continaed. ' ' 



Fenkstella erectipora. 



.rfl hna -onriai t.<.i. Page U8. 



tig. IB. A |M)rtion of the non-celluliferous face enlarged, showing the appearance and comparative size 

 ,.,,,,„ of the brauchea and disaepimeuts. (X t>.) 



1Hgf^,,Xfr ^ jiortion of the celluliferoiia face of the fi-ond with the carinse broken away, showing the form 

 and arrangement of the cell apertures. (X 6.) 



Upper Helderberg group. Ontario, Canada. 



Fenestella (Reteporina) uhomiufera. 



Page U9. 

 Pig. 18. A portion of the non-cellnliferous face of a frond which is much worn or macerated. The four 

 branches on the left of the fig-ure ai-e so much worn that the l)ases of the cells are exposed to 

 view ; the remaining branches are less worn, but the surface charactera are obsolete. (X 6.) 

 Pig. 19. A portion of the non-cellnliferous face of another frond, showing the branches well preserved 

 and anastomo.sing, with a prominent node at the center of each junction. The celluliferous 

 face in a jierfect 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 Jioy, Genesee comity, N. Y. 

 .kH'A'ilAKHV AJJHliwtiiia'i 



1o noilfn.i >vt£lns aV. 



