BIOLOGICAL CLASSIFICATION OF GENERA. 



The following biological classification is introduced for the sake of convenience to 

 aid in quickly classifying any of the genera considered in the Bibliographic List. 

 Like the latter it includes only American Ordovician and Silurian genera. 



.ANIMAL KINGDOM. 



Phyllum PORIFERA. 



Class SPONGLE. 



Subclass SlLICISPONGLE. 



Order Tetractinellida. 



Family Astylospongid.e Rauff. 



Astylospongia Roemer, Caryospongia Rauff, Caryomanon Rauff, ( 'arpospongta Rauff, 

 Cyathospongia Hall, Carpomanon Rauff, Palasomanon Rauff. 



Family Hindiid;e Rauff. 

 Hindia Duncan. 



Family AnomoclonelliD/55 Rauff. 

 Anomoclonella Rauff, Pycnopegma Rauff. 



Family Chiastoclonellid^} Rauff. 

 Chiastoclonella Rauff. 



Family Aulocopid^e Rauff. 

 Aulocopella Rauff, Aulocopium Oswald, Dendroclonella Rauff. 



Family Arch^eoscyphid/E Rauff. 

 Archseoscyphia Hinde. 



Family Rhizominnid.-e Zittel. 

 Nipterella Hinde. 



Family AnthaspidelliD/E Ulrich and Everett. 



Anthaspidella Ulrich and Everett, Calatliiura Billings, Climacospongia Hinde, Edrio- 

 spongia Ulrich and Everett, Eospongia Billings, Streptosolen Ulrich and Everel . 

 Streptospongia Ulrich, ?Trachyura Billings, Zittelella Ulrich and Everett. 



Family Dystactospongid^e Miller. 



Dystactospongia Miller, Heterospongia Ulrich, Saccospongia Ulrich, Strotosp 

 Ulrich and Everett. 



Order Hexactinellida. 



Family Protospongid/E Hinde. 



?Halichondrites Dawson and Hinde, ?Lasiotlnix Dawson and Hind.', Phormcsella 

 Hinde, Protospongia Salter, Stephanella Hinde. 



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