List of Genkra axd Si'fx;rES. 



Genus Thamnodictya, Hall. 

 T. Newberryi, Hall. T. Oi-toni, sp. nov. 



Genus Clepsydrospongia, gen. nov. 



C. matutina, sp. nov. 



Genus Cleodictya, Hall. 



C. Claypolei, sp. nov. C. Mohri, Hall. 



C. gloriosaj Hall. 



Subfamily PHYSOSPONGIINiE, subfain. nov. 

 Genus Physospongia, Hall. 

 P. Dawsoni, Whitfield (sp,). P. alternata, Hall. 



P. Colletti, Hall. P. multibursaria, sp. nov. 



Genus Roemerispongia, gen. nov. 

 R. Gerolsteinensis, F. Roemer (sp.). 



Subfamily HYPHANTiCNIINie, subfara. nov. 



Genus Hyphantenia, Vanuxem. 

 H. Chemungensis, Vanuxem. 



Subfamily HALLODICTYINiE, subfam. nov. 



Genus Hallodictya, gen. nov. 

 H. Sciensis, sp. nov. H. Cottoniana, sp. nov. 



Genus Actinodictya, Hall. 



A. placenta, Hall. 



Genus Cryptodictya, Hall. 

 C. Alleni, Hall. 



Subfamily AGLITHODICTYINiE, subfam. nov. 



Genus Aglithodictya, gen. nov. 

 A. numulina, sp. nov. 



DubitandcB sedis. 

 ? Genus Ectenodictya, Hall. 



? E. iinplexa, Hall. 



