69 



PLATE XXViL 



HYMERAPHIA VERTIOELLATA, Bowerbank. 



Vol. ii, p. 145, ' Mon. Brit. Spongiadse.' 



Fig. 1. Magnified view of a small piece of 

 the type-specimen of the sponge exhibiting the 

 numerous fusiformi-cylindrical, verticillately spined 

 spicula of the dermal membrane with a portion of the 

 shaft of a very large skeleton spiculum. X 250 linear. 



Fig. 2. Represents the basal end of one of the 

 large attenuato-clavate skeleton spicula. X 250 

 linear. 



Fig. 3. Represents the type-specimen of the sponge 

 of the natural size. 



Vol. i, Plate X, fig. 238, represents an adult verti- 

 cillately-spined spiculum of the dermal membrane of 

 the largest size. X 183 linear ; and fig. 239 re- 

 presents the incomplete development of the verti- 

 cillately-spined spiculum in its moniliform state. 

 X 183 linear. 



Fig. 240 in the same plate exhibits the incissurate 

 termination of one of the auxiliary skeleton spicula of 



/ 1 



H. verticellata. X 660 linear. 



I received a small pebble from my friend Mr. Peacli 

 in a bottle with spirit, part of the results of his 

 dredging at Shetland in the year 1864. On the top 

 of the stone there was a small conical sponge, ap- 

 parently a very young specimen of Hymeniacidon 

 suberea, and on the side of the stone a thin patch of 

 sponge very little exceeding the eighth of an inch in 

 diameter. On removing this and mounting it in 

 Canada balsam it proved to be a very young state of 

 Hymeraphia verticillata. The remarkable spiculous 



