103 



PLATE XLII. 



HALICHONDRIA DISTORTA, Bowerbank. 



Yol. ii, p. 240, ' Mon. Brit. Spongiadsa.' 



Fig. 1. Represents the specimen presented to me 

 by Mrs. Griffiths, obtained from the Brixham Trawler. 

 Natural size. 



Fig. 2. From a small portion of the dermal mem- 

 brane, exhibiting the polyspiculous network of that 

 organ. X 80 linear. 



Fig. 3. An average-sized acerate spiculum, from 

 the skeleton. X 80 linear. 



Fig. 4. An average-sized acuate, skeleton spiculum. 

 X 80 linear. 



