BRITISH SPONGTAD.E. 147 



hispid. Oscula and pores inconspicuous. Dermal 

 membrane inconspicuous. Skeleton and external 

 defensive spicula, attentuato-clavate, long and slender, 

 variable in length. Internal defensive spicula clavato- 

 attenuato-cylindrical ; apex stellately spinous. Basal 

 membrane pellucid, smooth, and even. Sarcode thick 

 and abundant. 



Colour. Dried, light amber yellow to orange yellow. 

 Habitat. Shetland, Mr. Barlee -, Moray Frith, Rev. 

 Walter Gregor ; Frith of Clyde, Rev. A. M. Norman. 

 Examined. In the dried state. 



I am indebted to my friend Mr. Barlee for two speci- 

 mens of this interesting species. They were taken by him 

 in the course of his deep-sea dredging at Shetland, in the 

 year 1858. They occupy the insides of two valves of dead 

 shells. In one of them, Bocinia lincta, there is a thin 

 patch of the sponge seven lines in length, and five in width. 

 In the other shell, Tapis aurita, there is a specimen very 

 similar in appearance to the first one, of six lines in dia- 

 meter. The appearance of the sponge in both cases is like 

 that of a thinly spread patch of gum or glue-water, dried 

 on the surface of the shell ; but with the aid of a lens of 

 an inch focus, and by a little management of the light, the 

 long projecting spicula of the sponge may be seen standing 

 out from its surface in abundance. The sponge is ex- 

 tremely thin, the height from the basal membrane to 

 the surface measured but ^gth inch ; and from the basal 

 membrane, whence the long spicula proceed, to the apex of 

 the longest spiculum in the field of the microscope, ^th inch. 



I could not detect either oscula, pores, or a dermal 

 membrane. When immersed in water the sarcode ex- 

 panded to rather above the line of the largest of the internal 

 defensive spicula, and the surface presented the usual 

 slightly undulating gelatinoid appearance of that substance, 

 but I could not detect either interstitial membrane or 

 cavities. 



The whole of the large spicula of the sponge serve the 



