163 



PLATE LXIII. 



Desmacidon Peaohii, Bowerhaiih. 



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



Fig. 1 — Repi'esents the type-specimen received 

 from Mr. Peach. JSTattiral 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 shox-t and somewhat stout ten- 

 sion spicula of the dermal membrane. X 630 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 630 linear. 



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

 tive spiculum from the interstitial membranes. X 

 630 linear. 



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

 spicula from the interstitial membranes. X 630 

 linear. 



Desmacidon iEGAGEOPiLA, Bowerhan'k. 



Vol. ii, p. 3.52, ' Mon. Brit. SpongiaJfe.' 



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

 slender-branching Fucus from Brighton. Natural 

 size. 



