HYMENIAOIDON. 73 



7. HYMENIAOIDON FIRMUS, Bow., Ill, 186 ; PI. LXXII, 



figs. 1, 2. 



Habitat. — Among Dr. Bowerbank's notes is — " I 

 received a very few small fragments of this sponge 

 for examination from the Eev. A. M. Norman, labelled 

 ' Yellow, "Westport Bay.' The microscopical sections 

 were in all respects identical with those of the type 

 specimen." 



8. HYMENIAOIDON PLAOENTULA, BoW., Ill, 189, 353 ; PI. 



LXXII, figs. 6—9. 



9. HYMENIAOIDON AEMIGER, BoW., n, Sp., IV, PI. IV, figS. 



10—17. 



" Sponge coating, thin. Surface smooth and even. 

 Oscula simple, minute. Pores inconspicuous. Dermal 

 membrane pellucid, abundantly spiculous ; tension 

 and defensive spicula attenuato-acuate, entirely spin- 

 ous, irregularly dispersed, variable in size ; retentive 

 spicula bidentate or tridentate, equi-anchorate, very 

 minute, rather numerous. Skeleton — spicula fusi- 

 formi-acerate, numerous, small, and rather short; 

 internal defensive spicula same as those of the dermis, 

 few in number ; retentive spicula same as those of the 

 dermis, not numerous. 



" Colour. — In the dried state, cream- white. 



"Habitat. — Roundstone Bay, Ireland; Rev. A. M. 

 Norman. 



" Examined. — In the dried state. 



