112 A MONOGRAPH OF THE 



a slight extent beyond it. Each of the fasciculi consists of 

 a great number of spicula, and the radiation is frequently 

 to such an extent as to form an angle of twenty or thirty 

 degrees. In the spaces intervening between the fasciculi 

 there is very rarely even a single spiculum to be seen 

 passing from the axis of the sponge to its surface. 



I could not separate the dermal membrane from the 

 mass of sarcode beneath it, but it is evidently thin, simple 

 and transparent, and apparently destitute of spicula. 



The thick cylinder of sarcode surrounding the axial 

 skeleton is uniform in its texture, and without any appear- 

 ance of cavities or canals, and there are thinly and irregu- 

 larly scattered through the whole of its substance, a few 

 stellate spicula, with about six or eight attenuating radii. 

 These spicula are very minute, not exceeding j^th inch 

 from point to point of the radii, and require a power of 

 about 600 linear to exhibit them in a satisfactory manner. 



The axial skeleton of this species is more complex in its 

 structure than that of many of the allied species. The 

 spicula of which it is composed are very slender, frequently 

 flexuous and very numerous. Although at first sight this 

 species may be readily confounded with slender specimens 

 of D. stuposa] its anatomical differences readily distinguish 

 it from that sponge. 



I subsequently obtained from Mr. Henry Ridley, of 

 Hastings, a much larger specimen of this sponge, it rather 

 exceeded eight inches in height ; like the first specimen, it 

 had not the natural base, but the lower portion of the stem 

 was two and a half lines in diameter. In every other cha- 

 racter, except the size, it closely resembled the specimen I 

 received from Mr. Tumanowicz. Although a more mature 

 and much larger specimen than the type one and in a per- 

 fectly dry condition, I could not detect any protrusion of 

 spicula through the dermal membrane. In this specimen, 

 and in one obtained by the Rev. A. M. Norman from Mr. 

 Cooper, of Guernsey, the whole of the branches are deve- 

 loped in the same plane ; but in the specimen presented to 

 Mr. Norman by Miss Le Lievre this is not the case, but 

 the latter specimen has the appearance of having been dis- 



