PLATE XXI. 55 



state of preservation, aiid foi- aftbi'diug a good view of 

 both surfaces of the sponge by the hirge natural 

 fokling of the expanded surface of the sponge. The 

 Rev. A. M. Norman has a specimen of this species 

 formed of t^vo sponges -which have grown together at 

 their margins, and each of these has a fokhng of their 

 proximal margins so, as it were, to avoid touching each 

 othei' as much as possible. The width of the double 

 specimen is seven inches, and the height of the largest 

 one four inches. 



Figs. 1-1, 15. — Two of the skeleton spicula from the 

 axial colunrn. X 80 linear. 



Figs. 16, 17. — An acerate and an acuate spiculum 

 from the I'amuli. X 80 linear. 



These two forms of spicula are common to the 

 dermal surface as well as to the ramuli. 



