BRITISH SPONGIADiB. 127 



2. MiCROcioNA L^vis, Bowerbank. 



Sponge. Coating thin ; surface even and smooth. Oscula 

 simple, dispersed, minute. Pores inconspicuous. 

 Dermal membrane spiculous; spicula attenuato-ace- 

 rate, subclavate, long and slender, subfasciculate ; and 

 tricurvo-acerate, stout, central curve abrupt, dispersed, 

 numerous. Skeleton : columns short and stout ; 

 spicula numerous, slightly divergent ; attenuato-acuate, 

 large and long. Internal defensive spicula attenuato- 

 acuate, short, entirely spined ; spines incipient, dis- 

 persed. Interstitial membranes, tension spicula 

 tricurvo-acerate, stout, central curve abrupt, very 

 numerous. 



Colour. — Nut-brovra, when dried. 

 Habitat. — Shetland, Mr. Barlee. 

 Examined. — In the dried state. 



I am indebted to my late friend Mr. Barlee for my 

 knowledge of this species. I received from him a single 

 specimen, which covered the whole of the imperforate valve 

 of a Terebratula caput-serpentis, and not quite an inch in 

 length. In the dried conditioii the surface is even, but 

 somewhat rough, but small portions from the parts in best 

 preservation, when .immersed in water, presented a smooth 

 and even appearance, and I could not detect any projecting 

 spicula. 



The oscula are not readily determinable, but they 

 appear to be simple and dispersed. The subclavate at- 

 tenuato-acerate tension spicula of the dermal membrane 

 are very long and slender. Sometimes they are loosely 

 fasciculated. Its bundles do not assume any especial 

 direction, but the bases of the spicula of the fasciculi 

 appear to be always coincident. Many other separate 

 spicula of the same form are irregularly dispersed on the 

 inner surface of the dermal membrane. The tricurvo- 



