BRITTSH SPONGIADiE. 223 



being at one end of them and all their apices at the other, 

 and they were also not more than about half the length of 

 the dispersed ones. 



37. Hymeniacidon paupertas, Bowerbank. 



Sponge. Sessile, coating. Surface very irregular, strongly 

 hispid. Oscula inconspicuous, simple, dispersed, 

 minute. Pores inconspicuous. Dermal membrane 

 pellucid, furnished abundantly with sub-fusiformi 

 cylindrical spicula, dispersed or loosely fasciculated. 

 Skeleton ; spicula attenuato-clavate, basally spined, 

 large and long. External defensive spicula, same as 

 those of the skeleton. Internal defensive spicula, 

 attenuato-clavate, entirely spined. Retentive spicula, 

 expando-tridentate equi-anch orate, very stout and 

 strong. Interstitial membranes, tension spicula, same 

 as those of the dermal membrane. 



Colour. Dark amber. 



Habitat. Shetland, parasitical on Zoophytes, Rev. A. M. 

 Norman. 



Examined. In the dried state. 



The appearance presented by this sponge is very poor 

 and uninviting. It coats the stem of a Zoophyte for about 

 two inches of its length so thinly and irregularly, as at first 

 sight to induce the idea that it is in a very early and im- 

 mature stage of growth, instead of being in a completely 

 adult state. The surface is extremely cavernous and uneven, 

 and the hispidation, which is produced by the large external 

 defensive spicula, is very prominent ; the spicula projecting 

 from all parts of the surface and into the cavernous depres- 

 sions for nearly the whole of their length. The dermal 

 membrane is thickly covered with either dispersed or fas- 

 ciculated sub-fusiformi-cylindrical spicula ; the fasciculi are 

 loosely gathered together into wide flat bundles, which 

 have no regularity in their mode of disposition. In the 



