163 



PLATE LXIII. 



DESMACIDON PEAOHII, BowerbanJc. 



Vol. ii, p 349, ' Mon. Brit. Spongiadse.' 



Fig. 1 Represents the type-specimen received 

 from Mr. Peach. Natural size. 



Fig. 2. A skeleton spiculum of about the average 

 size. X 80 linear. 



Fig. 3. A long and very slender acerate tension 

 spiculum from the interstitial membranes. X 530 

 linear. The normal form of these spicula is very 

 slightly curved, but they are frequently more or less 

 sinuous, and sometimes curved at one of their ex- 

 tremities, as represented in the figure. 



Fig. 4. One of the short and somewhat stout ten- 

 sion spicula of the dermal membrane. X 530 linear. 

 These spicula are also very abundant on the interstitial 

 membranes. 



Fig. 5. A large and somewhat contort, bihamate, 

 retentive spiculum from the interstitial membranes. 

 X 530 linear. 



Fig. 6. A large, reversed, simple, bihamate, reten- 

 tive spiculum from the interstitial membranes. X 

 530 linear. 



Fig. 7. One of the smallest bihamate, retentive, 

 spicula from the interstitial membranes. X 530 

 linear. 



DESMACIDON ^GAGEOPILA, Bowerbank. 



Vol. ii, p. 352, ' Mon. Brit. Spongiadse.' 



Fig. 8. Represents a specimen of the species on a 

 slender-branching Fucus from Brighton, Natural 

 size. 



