1 5;-. 



PLATE LXI. 



Desmacidon peuticosa, Boioerhunl-. 



Vol. ii, p. 345, ' Mon. Bi'it. Spongitidc«.' 



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 spiculnm. 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 

 spiculnm from the dermal membrane. X 530 linear. 



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

 spiculnm from the dermal membrane. X 630 linear. 



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

 tive spiculum from the dermal membrane. X 630 

 linear. 



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

 spicula from the dermal membrane, x 530 linear. 



