BRITISH SPONGIADjE. 141 



M. armata; the general aspect of the two when mounted as 

 sections in Canada balsam are very similar, but the greater 

 length and strength of the terminal spicula of the skeleton 

 columns, the powerfully recurvedly spinous internal defen- 

 sive spicula, and the anguloid tricurvate-acerate tension 

 spicula so abundant on the interstitial membranes of M. 

 armata, on a closer examination readily separate the two 

 species. 



Gen us H y m e r ap h i a, Bow orb an k , 



Section * * Skeleton spicula, acuate. 



1. Hymeraphia vermiculata, Bowerbank. 



2. clavata, Bowerbank. 



Section * * * Skeleton spicula, spinulate. 



3. Hymeraphia verticillata, Bowerbank. 



4. stellifera, Bowerbank. 



1. Hymeraphia vermiculata, Bowerbank. 



Sponge. Coating ; surface uneven and cavernous ; strongly 

 hispid. Oscula simple, dispersed. Pores inconspicuous. 

 Dermal membrane spiculous ; spicula acuate, long, 

 and exceedingly slender, variable in size ; fasciculated ? 

 Skeleton and external defensive spicula acuate, large 

 and long. Spicula of the basal membrane inequi- 

 acerate, vermiculoid, rather large and stout, exceed- 

 ingly variable in tortuosity. 



Colour. Dried, light buff yellow. 



Habitat. Shetland, in deep water, Mr. Barlee, Mr. 

 C. W. Peach, and Rev. W. Gregor. 

 Examined. In the dried state. 



