155 



PLATE LXI. 



DESMACIDON FEUTICOSA, Bowerbank. 



Vol. ii, p. 345, ' Mon. Brit. Spongiadse.' 



Fig. 1. Represents a fine specimen of the specie^ 

 based on a large pebble from the Diamond Ground, off 

 Hastings. Half the natural size. 



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

 250 linear. 



Fig. 3. One of the tension spicula of the dermal 

 membrane. X 250 linear. 



Fig. 4. A large-sized, contort, bihamate, retentive 

 spiculum from the dermal membrane. X 530 linear. 



Fig. 5. A small-sized, simple, bihamate, retentive 

 spiculum from the dermal membrane. X 530 linear. 



Fig. 6. A large, bidentate, equi-anchorate, reten- 

 tive spiculum from the dermal membrane. X 530 

 linear. 



Fig. 7. One of the small, equi-anchorate, retentive 

 spicula from the dermal membrane. X 530 linear. 



