93 



PLATE XXXVII. 

 HYMENIACIDON SULPHUEEA, 



Vol. ii, p. 208, ' Mon. Brit. Spongiadee.' 



Fig. 1. Represents the type-specimen presented to 

 me by Mr. Bean, of Scarborough. Natural size. 



Fig. 2. One of the skeleton spicula. X 250 

 linear. 



Fig. 3. A tension spiculum of the dermal mem- 

 brane. X 250 linear. 



HYMENIACIDON PAUPERTAS, Bon-erbank. 



Vol. ii, p. 223, ' Mon. Brit. Spongiadse.' 



Fig. 4. Represents the type-specimen in the cabinet 

 of the Rev. A. M. Norman. Natural size. 



Fig. 5. One of the sub-fusiformi cylindrical spicula 

 of the dermal membrane. X 250 linear. 



Fig. 6. An attenuate -clavate, basally-spined skele- 

 ton spiculum. X 250 linear. 



Fig. 7. One of the attenuato-clavate, internal, 

 defensive spicula. X 250 linear. 



Fig. 8. - - An expando-tridentate, equi-anchorate, 

 retentive spiculum. X 530 linear. 



HYMENIACIDON SUBCLAVATA, BowerdanL 



Vol. ii, p. 209, ' Mon. Brit. Spongiadse.' 



Fig. 9. Represents the type-specimen of the species 

 from Tenby. Natural size. 



Fig. 10. One of the slender fusiformi-subclavate 

 spicula from the dermal membrane. X 250 linear. 



Fig. 11. One of the skeleton spicula. X 250 

 linear. 



Fig. 12. A contort, bihamate, retentive spiculum, 

 X 530 linear. 



Fig. 13. One of the minute, bidentate, inequi- 

 anchorate, retentive spicula. X 530 linear. 



