165 



PLATE LXIV. 



Raphyrus Gripfithsii, Boiverbank. 



Vol. ii, p. 354, ' Mon. Brit. Spongiada;.' 



Fig. 1. — Represents a specimen seated on the shell 

 of a large oyster, which it overlaps on every side. 

 The whole of the sponge is thickly studded with in- 

 halent areas, while at the upper portion of the figure 

 there are a number of large oscula in an irregularly 

 curved line. Natural size. 



Figs. 2 and 3. — Spicula of the skeleton, x 250 

 linear. 



Figs. 4 and 5. — Spicula of the interstitial membranes. 

 X 250 hnear. 



Vol. i, Plate XIII, fig. 265, represents a ^oortion of a 

 small skeleton fibre composed of innumerable spicula, 

 irregularly mixed. X 175 linear. 



