HYMENIACIDOX. 73 



7. HYMENIACIDON FIRMUS, Bow., -in, 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 Rev. A. M. Norman, labelled 

 1 Yellow, Westport Bay.' The microscopical sections 

 were in all respects identical with those of the type 

 .specimen." 



8. HYMENIACIDON PLACENTULA, Bow., in, 189, 353 ; PI. 

 LXXII, figs. 59. 



9. HYMENIACIDON ARMIGER, Bow., n. sp., iv, PI. IV, figs. 

 1017. 



" 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. 



