210 PLATE t/XXIV. 



Oscula simple, very numerous. Pores inconspicuous. 

 Dermal membrane spiculous ; tension spicula acuate, 

 slender, very nearly as long as those of the skeleton, 

 few in number ; also tricurvato-acerate, very long and 

 slender, nearly straight, sometimes flexuous ; central 

 curve abruptly angulated or looped, rather numerous ; 

 retentive spicula dentato-palmate, equianchorate, very 

 minute and symmetrical, few in number. Skeleton, 

 equably reticulate ; rete stout and polyspiculous ; 

 spicula sub-attenuato acerate, stout and strong, mode- 

 rately long. Interstitial membranes jDellucid; fur- 

 nished with the same forms of spicula as the dermal 

 membrane, but more sparingly. 



Colour. — In the dried state, liglit brown. 



Habitat. — Shetland, ninety-six fathoms. Rev. A. 

 M. Norman. 



Examined. — In the dried state. 



I received two small pieces of this sponge 

 from Mr. Norman. The largest was two inches in 

 length, and at the thickest end slightly exceeded half 

 an inch in average diameter. The smaller piece was 

 not quite an inch in length, and of about the same 

 diameter as the larger one ; both of them appear as if 

 they had been scraped off from a large shell or 

 stone, and probably had formed parts of the same 

 sponge. 



The surface is strikingly characteristic. It has the 

 appearance of an irregular and very ojoen network, the 

 areas of which are many of them nearly a line in 

 diameter. 



These areas have everyappearance of beingtheoscular 

 orifices of the sponge, no other such organs being appa- 

 rent. The rete of this open network of skeleton tissue 

 is formed of the ordinary reticulate skeleton of the 

 sponge, covered by a delicate transparent dermal 

 membrane, containing the appropriate spicula of that 

 organ ; and these spicula ai-e also strikingly charac- 

 teristic of tlie species. The slender acuate tension 

 spicula are often two thirds or three fourths of the 



