101 



PLATE XLI. 



Halichondeia glabra, Brnverhanl-. 



Vol- ii, p. 232, ' Mon. Biit. Spongiadas.' 



Fig. 1. — A specimen of the species from Scar- 

 borougli. Natural size, the lighter and upper por- 

 tion of the figure representing the sponge. 



Fig. 2. — A fully-developed skeleton spiculum. x 

 250 linear. 



Fig. 3. — An immature skeleton spiculum. X 250 

 linear. Intermediate sizes between figs. 2 and 3 are of 

 frequent occurrence. 



HALionoNDEiA angulata, Boiverhcm/c. 



Vol. ii, p. 233, ' Mon. Brit. Spongiadae.' 



Fig. 4. — Represents the type-specimen from 

 Guernsey in the cabinet of the Rev. A. M. Norman. 

 Natural size. 



Fig. 5. — A small piece of the dermal membrane, 

 exhibiting the structure of its uuispiculous network. 

 X 80 linear. 



Fig. 6. — Oue of the skeleton spicula. X 250 

 linear. 



Fig. 7.' — A small and slender acorate, tension spi- 

 culum. X 250 linear. 



Fig. 8. — Oue of the subangulated, tricurvate 

 acerate, tension spicula. X 530 linear. 



Halichondeia caduca, Bowerbank. 



Vol. ii, p. 234, ' Mon. Brit. Spongiadte,' 



Fig. 9.' — Represents the type-specimen from the 

 northern side of St. Catherine's rock, at Tenby, in the 

 dried state. Natural size. 



Fig. 10. — Represents two lai'ger and more fully 

 developed specimens preserved in spirit from Guernsey. 

 In the cabinet of the Rev. A. M. Norman. Natural 



