OF THE SPONGIADJE. 233 



FIG. 

 33. SUB-ATTENUATO ENTIRELY SPINED CYLINDRICAL. 



From Hymeniacidon Cliftoni, Bowerbank, MS. 

 Freemantle, Western Australia. X 400 linear. 



34. CLAVATO-ATTENUATO-CYLINDRICAL, APEX STELLATELY 



SPINOUS. From Hymerapkia sf el/if era, Bower- 

 bank. X 260 linear. All the spicula of this 

 sponge appear to combine the offices of skeleton 

 and defensive spicula, Page 189. 



35. ELONGO-ATTENUATO- STELLATE. Having the radii 



springing from an elongated instead of a central 

 base. This form of spiculum occurs abundantly 

 in Tetliea vmricata, Bowerbank, MS. From 

 Vigten Island, Norway. It is both externally and 

 internally defensive. X 308 linear, Page 22. 



36. EQUIANGULAR TRIRADIATE. Having the three attenu- 



ating rays in the same plane, and the intervening 

 angles equal, or very nearly so. Grantia com- 

 pressa, Fleming. X 160 linear, Page 163. 



37. RECTANGULAR TRIRADIATE. Having the three attenu- 



ating rays in the same plane, two of them forming 

 a straight line, and one being projected from the 

 middle of the line, forming right angles to it. 

 Abundant in the base of the ciliary fringe of the 

 mouth of the cloaca of Grantia tessellata, Bower- 

 bank. X 260 linear. 



38. ELONGO-EQUIANGULATED TRIRADIATE. From Grantia 



striatula, Bowerbank, MS. X 108 linear. Ma- 

 deira. Exhibiting an extreme development of the 

 elongated ray. This form occurs also in the 

 intermarginal cavities in Grantia compressa. 



39. EXFLECTED ELONGO-EQUIANGULATED TRIRADIATE. 



From Grantia striatula, Bowerbank, MS. XlOS 

 linear. Madeira. Abundant on the surface of 

 the pedicel of the sponge ; and also Grantia 

 compressa, see Fig. 312. 



40. EQUIANGULAR TRIRADTATE. A very stout variety of 

 form, from an undescribed African calcareous 

 sponge. X 90 linear. 



