188 PLATE Lxxri. 



smootli and even. Oscula simple and dispersed, few 

 in number. Pores inconspicuous. Dermal membrane 

 tough and strong, spiculous ; spicula very abundant, 

 irregularly and thickly felted together, acuate, same 

 size and form as those of the skeleton. Skeleton. — 

 Radiating confusedly towards the dermal surface in 

 very loosely compacted fasciculi ; spicula acuate, 

 very abundant. 



Colour. — In spirit, pale ochreous yellow, with a shade 

 of green. 



Habitat. — Jersey; Eev. A. M. Norman. 



Examined.- — From spirit. 



The specimen described is the only one I have yet 

 seen. It is one and three quarters inch broad, one 

 inch high, and half an inch thick at its base, whence 

 it becomes gradually thinner, until at the distal margin 

 it does not exceed one eighth in thickness. Both the 

 broad surfaces are slightly undiilating with a few 

 shallow depressions. The oscula ai^e small, very few 

 exceeding half a line in diameter. The dermal mem- 

 brane is remarkably abundant in spicula, and they are 

 closely felted over each other in every direction. The 

 most striking specific character is in the singular 

 arrangement of the skeleton tissues which present a 

 compact radiating structure throughout the whole of 

 its substance ; the like of which I have never observed 

 in any other species belonging to the same section of 

 the genus Hymeniacidon ; but in the following section 

 of the genus with spinulate spicida this radiating mode 

 of the spicula arrangement may be observed in H. 

 suberea and carnosa, to a certain extent beneath the 

 dermal surfaces, while in the deeper seated parts of 

 the sponges the usual forms of the characteristic 

 structures of the genus may be observed. The size 

 and form of the skeleton spicula are so like those of 

 several other nearly allied species that they are of very 

 little use in discriminating the species. 



