.58 



PLATE XXI. 



DICTYOCYLINPRUS PUMiLUS, Bowerlank. 



Yol. ii, p. 114, ' Mon. Brit. Spongiadse.' 



See pi. XIX, fig. 19, vol. iii, for a representation of 

 the sponge. In consequence of the great number of 

 the spicula required to illustrate the other three species 

 represented in that plate, those belonging to D. 

 purailus were forced to be given in another plate. 



Fig. 1. A large, acuate, skeleton spiculum from the 

 axis of one of the columns. X 80 linear. 



Fig. 2. -The basal portion of a spinulate skeleton 

 spiculum. X 80 linear. 



Fig. 3. A slender, acerate, tension spiculum. X 80 

 linear. 



Fig. 4. One of the internal defensive spicula. X 250 

 linear. 



DICTYOCYLINDRUS ACULEATE, Bowerlank. 



Yol. ii, p. 109, ' Mon. Brit. Spongiadse.' 



Figs. 5, 6. Represent specimens dredged off Scar- 

 borough by Mr. Bean. 



Fig. 7. A larger and more fulry-developed specimen 

 of D. aculeatus dredged off the Northumberland coast- 

 by Mr. Albany Hancock, to whom I am indebted for 

 this very illustrative specimen. This sponge was 

 soaked in water for some hours before it was drawn, 

 to restore it as nearly as possible to the condition in 

 which it was when in the living state. Natural size. 

 The spicula of this species are from the type-specimen 

 of the species presented to me by my late highly- 

 esteemed friend Mr. Bean, of Scarborough. 



