Explanations ok Platks, 309 



GRIPHODICTYA, gen. nov. 



Page 179. 



Gripiiodictya epipiianes, sp. nov. 



Page 180. 



Figure 6. The specimen from which the spicules represented on page 180 

 were taken. This sponge has to some degree the aspect of 

 Phragmodictya catilliformis, but its characteristic spicules have not 

 been found in any other species. 

 Keokuk group. OrawfordsvilU, Indiana. 



HYDRIODICTYA, gen. nov. 



Page 77. 

 (See Plates IV, V, XVI, XXI.) 



Hydriodictya ctlix, sp. nov. 



Page 78. 

 (See Plates V and XVI.) 



Figure 7. An enlargement of a portion of the specimen given on Plate xvi, 

 fig. 2, showing a part of the repaired net-work of the skeleton. 

 Chemung group. Deyo hasin, Naples, N. Y. 



