84 PLATE XXXIII. 



HYMENIACIDON MACILENTA, Bowerbank. 



Fig. 7. Three specimens of the species from the 

 Island of Herm, by the Rev. A. M. Norman. Natural 

 size. 



By an oversight of the artist the skeleton spicnlum 

 of this species has been omitted in the Plate, but it so 

 happens that the skeleton spiculum of Hymeniacidon 

 fallav, represented by fig. 17 in the same plate, is of 

 the like form and proportions as that of H. macilenta. 

 I must therefore refer to that figure as a sufficient 

 representative of the skeleton spiculum of the species 

 in course of description. 



Fig. 8. One of the sub-clavate, acuate, slender, 

 dermal, tension spicula. X 150 linear. 



Fig. 9. One of the slender, tricurvato-acerate, 

 tension spicula of the dermal membrane. X 150 

 linear. 



Figs. 10 and 11. --Two of the contort-bihamate reten- 

 tive spicula. X 150 linear. 



Fig. 12. One of the iuequi-dentato-palmate reten- 

 tive spicula of the dermal membrane. X 530 linear. 



Fig. 13. An inequi-bidentate, retentive, spiculum 

 from the dermal membrane. X 530 linear. 



HYMENIACIDON VAEIANTIA, Bowerbanlc. 



Vol. ii, p. 174, ' Mon. Brit. Spongiadse.' 



Fig. 14. Represents the type-specimen of the 

 species. Natural size. 



The spicular illustrations required more space than 

 could be assigned to them in the plate in which the 

 sponge is figured in the order in which it is arranged 

 in vol. ii. They will be found as follows in plate XL V 

 of this volume. 



