AFFINITIES OF THE GENTJS PROTOSPONGIA. 367 



Dr. Hicks described his discovery of Protosponfjia. He had never 

 found it otherwise than pyritized. This condition, he had observed, 

 was particularly common in fossilized horny organisms in the Cam- 

 brian rocks. 



The President remarked on the abundance of pyritized remains 

 at certain horizons, and on the value of the collection made bj 

 Dr. Hicks from the Cambrian rocks. 



Mr. SoLLAs said he inclined to the view that Protospongia was 

 part of the dermal structure ; but still it was strange that no other 

 part was found, and so far as the evidence went it was quite as 

 strong for the sponge being complete. As for the occurrence of 

 pyritized fossils, one might expect that under similar circumstances 

 fossils would be similarly preserved. 



