PLATE LXXXI. 259 



Oscula on inner surface, simple, variable in size, very 

 numerous. Pores on outer surface, conspicuous, very 

 numerous. Dennis thin, pellucid, outer surface 

 furnished with a stout polyspiculous irregular reticu- 

 lation ; on the inner one with numerous dispersed 

 tension spicula large and small ; spicula subfusiformi- 

 acerate ; and also with numerous attenuate-stellate, 

 and minute atteuuato-elongo-stellate, retentive spicula. 

 Connecting spicula expando-ternate, radii attenuated, 

 very long ; shafts very short. Skeleton. Fasciculi 

 and reticulations stout and polyspiculous ; rete open 

 and irregular ; spicula subfusiformi-acerate, long and 

 large. Interstitial membranes. Pellucid, furnished 

 abundantly with small subfusiformi-acerate tension 

 spicula, and with numerous retentive spicula of the 

 same form as those of the dermal membrane. Gemmules 

 membranous, aspiculous. 



Colour. In the dried state, light grey. 



Habitat. Shetland, 110 fathoms ; Rev. A. M. 

 Norman. 



Examined. In the dried state. 



The form of this sponge is that of an irregular com- 

 pressed cup with very thick parietes ; it has been torn 

 from its natural attachment ; the basal portion in its 

 present state is three inches long by one inch in thick- 

 ness, and it has every appearance of having been 

 sessile. 



The specimen under consideration is composed of 

 two individuals united by approximation, and both 

 present a marked disposition to the cupshaped form. 

 The largest of the two is four and a quarter inches in 

 length at its distal portion, and the smaller one 

 slightly exceeds two inches. The breadth of the 

 larger one does not exceed two inches, and the height 

 of each is rather more than two inches. The margins 

 of the cups are irregularly rounded. The general 

 aspect of the surfaces of the sponge is strikingly charac- 

 teristic ; the beautiful minute reticulation of the outer 

 or inhalent surface is strongly contrasted with the 



