Prof. W. Thomson on the " Vitreous " Sponges. 123 



betray the universal type. One set of the sarcode-spicules of 

 AphrocalUstes^ is almost identical with the " furcated spiculated 

 biternate" spicule figured from Farrea occa (British Sponges 



vol. i. fig. 199), but more spiny. I am afraid to name this form 

 but i am sm-e it would be highly suggestive to Dr. Bower- 

 bank. 



