PLATE LIII. 



GtROOERAS UNtiULATUM. 

 Page 378. 

 See Plate 54. 

 Fig. 1. Latei-al view of a specimen showing the number of the volutions and the nodes on the internal mould, 

 corresponding to the subtubular expansions or spines on the test. Upper Helderberg lime- 

 stone. Cherry Valley, N. T. 

 Figs. 3, 4. A septum and transverse section of a fragment, which is compressed, and does not show the 



natural broadly ovate, subtriangular form of the tube. 

 Pig. 6. A section of the disc of an example, showing the depth of the air-chambers, where the walls of the 



tulKi and the septa have not been destroyed. Cherry Valley, N .Y. 

 Pig. 6. Another septate fragment, showing the regularity in the depth of the air-chambers. Cherry VxU- 

 Uy, N. Y. 



