162 PLATE LXII. 



DESMACIDON JEFFREYSII. 



Sponge massive, more or less spherical, externally, 

 crustaceous; internally, a mass of interstitial mem- 

 branes abundantly furnished with spicula; basally 

 attached to rocks or stones by stout, prehensile, root- 

 like organs ; apically furnished with large and small 

 penicillate tubular cloacae. Surface smooth. Oscula 

 within the cloaca?. Pores inconspicuous. Dermal 

 membrane pellucid, furnished with a unispiculous reti- 

 culation. Spicula same as those of the skeleton ; 

 retentive spicula bihamate, simple and contort, abun- 

 dant and very minute. Skeleton stout, coarse, and 

 elongately diffuse ; spicula acerate, rather short and 

 stout. Interstitial mass, membranes abundantly spi- 

 culous, without admixture of spiculo-fibrous structure ; 

 spicula of the membranes same as those of the ske- 

 leton ; retentive spicula, simple and contort bihamate, 

 very abundant, exceedingly minute. Gemmules mem- 

 branous. 



Dried. Light buff colour, 



Hob. Shetland ; Mr. C. W. Peach and Rev. A. M. 

 Norman. 



Examined. In the dried state. 



