184 PLATE LXXI. 



I have no doubt that both these forms will be found 

 in much larger quantities in future specimens of this 

 sponge in a better state of preservation. 



The presence of these forms of retentive spicula 

 should therefore be added to the specific description of 

 the species in vol. ii, p. 350 of ' Mon. Brit. Spon- 

 giadas.' 



