223 



TABULAR LIST OF SPECIES, 



ARRANGED IN STRATIGRAPHICAL SEQUENCE. 



The asterisk indicates that the forms thus marked occur in British strata. 



PALEOZOIC. 



CAMBRIAN SYSTEM. 



Order Hexactinellid^. 

 *Protospongia fenestrata^ Salter. 



ORDOVIAN SYSTEM. 



Order Hexactinellid^. 



Brachiospongia digitata, D. Owen. 

 *Hyalostelia parallela, M'Coy. sp. 

 *Hyalostelia fasciculus, M'Coy, sp. 



SILURIAN SYSTEM. 



Order Monactinelliu^. 

 Climacospongia radiata, Hinde. 



Order LiTHisTiDiE. 



Hindia fibrosa, Rmm. sp. 

 Aulocopium cylindraceum, Ram. 



Incekt.e sedis. 

 *Amphispongia oblonga, Salt. 



Order IIexactinellidjj. 



Astylospongia prsemorsa, Goldf. sp. 



Astylospongia stellatim-sulcata, Rwm. 



Astylospongia inciso-lobataj Rccm. 



Astylospongia imbricato-articulata, Rwm. 



Astylospongia Roemeri, Hinde. 



Palseomanon cratcra, Rwm. 

 *Dictyopbytou Daubyi, M'Coy, sp. 

 *Plectoderma scitulum, Hinde. 



Astrseospongia ineniscus. Ram. 



Astrseospongia patina, Rwm. 



