119 



PLATE XLVII. 

 HALICHONDRIA INORNATUS, Bowerbank. 



Vol. ii, p. 271, ' Mon. Brit. Spongiadse.' 



Fig. I. Represents the type-specimen sent to me 

 by Mr. Peach, with the type-specimen of Halichondria 

 simplex, fig. 5, closely incorporated with it, on the 

 upper part of the specimen. Natural size. 



Fig. 2. An average-sized, skeleton spiculum. 

 X 150 linear. 



Fig. 3. A young spiculum, from the interstitial 

 membranes of the sponge. X 150 linear. 



Fig. 4. A simple, bihamate, retentive spiculum, 

 from the dermal membrane. X 530 linear. 



HALICHONDRIA SIMPLEX, Boiverbank. 



Vol. ii, p. 246, ' Mon. Brit. Spongiadse.' 



Fig. 5. Represents the type-specimen of the 

 species, incorporated with the mass of Halichondria 

 inornatus, fig. 1, sent to me by Mr. Peach. Natural 

 size. 



Fig. 6. A skeleton spiculum, of the normal form. 

 X 80 linear 



Fig. 7. One of the flexuous skeleton spicula. 

 X 80 linear. 



RAPHIODESMA LINGUA, 



Hymeniacidon lingua, Bow. ' Mon. Brit. Spongiadse,' vol. ii, 



p. 187. 



A portion of the skeleton of the specimen repre- 

 sented by fig. 1, Plate LXXV, illustrating the faggot- 

 like fasciculation of the skeleton structure, on which 

 the genus is founded. X 60 linear. 



