PLATE XIX. 



ECTENODICTYA IMPLEXA. 

 Page 4T5. 

 Fig. 1. Lateral view of a specimen showing the constrictions and large ob- 

 scure bullae. Wa/oerly group, Warren, Pa. 



DlCTYOPHYTON (ClATHROSPONGIA) ABACUS. 

 Page 474. 



Fig. 2. A specimen (found in the interior of the preceding), showing the conical 

 form, the ridges bearing the concentric and radiating laminar 

 expansions, and obscurely the finer reticulations. Two of the 

 longitudinal alas are represented as they are imbedded in the 

 surrounding rock. Besides this species several fragments of 

 another distinct form are represented on the right of the prin- 

 cipal figure, which may belong to the inclosing frond of E. 

 implexus. 



Fig. 3. A small fragment of a cone, showing more distinctly the alternating 

 surface lines, and the reticulate character of the lamellate ex- 

 pansions. 



Fig. 4. A partial restoration of a portion of fig. 2, to show the true character 

 of the walls of the cone. The features here represented have 

 all been distinctly observed in the specimens. 



Waverly group, Warren, Pa. 



DlCTYOPHYTON TENUE. 

 Page 474. 

 Fig. 5. A fragment showing two depressions or the impressions of two tuber- 

 cles, and preserving very fine longitudinal and transverse striae. 



Waverly group, Warren, Pa. 



