66 



The sponge consists (see fig. Hi & 17) of a main stem, the lower end of which divides 

 itself into numerous finely ramified roots, by which it is fixed in the ooze. From this main 

 stem — at a greater or less distance from the root, and at nearly right angles on dift'erent 

 sides — issue undivided lateral branches of the same nature as the stem, and like it, termi- 

 nating in a somewhat enlarged obtusely rounded point. Everywhere, as well from the stem 

 as from the side-branches, there issue again secondary continuations in the form of thin 

 conical pointed and somewhat curved processes, all about of the same length, and usually 

 arranged, with short intervals, circularly around the stem or side-branches. Towards the ex- 

 treme end of the latter they become gradually shorter and more obtuse (see fig. 21) and at 

 last they disappear entirely, so that it looks as if the enlarged end had been produced by a 

 confusion- of these processes with each other and with the branches. As regards the side- 

 branches themselves they are of somewhat different length, and seem usually to be longest 

 nearer to the base of the sponge, and to decrease successively in length towards the point 

 of the stem. The branches as well as the main stem are very thin, of the same thickness, 

 and mostly quite straight. But on the other hand the secondary processes are as already 

 stated, always more or less strongly and evenly curved towards the point in one direction or 

 in another, and strongly compressed laterally. 



The color is in fresh specimens yellowish transparent, more or less going over to 

 reddish yellow; and the height of the largest specimens is about 60 Mm. 



Such is the exterior appearance of this peculiar sponge, which, as may be seen, is 

 very different from anything previously known. 



Closer investigation shews that the whole sponge is supported, and receives its form 

 by means of numerous very long siliceous vspicula of the form called by Bowerbank fusiformi- 

 acuate, which lie longitudinally close together, and are united with each other by a cementing 

 substance in close and solid fascicles. These needle-shaped spicula form everywhere the 

 more solid axis, round which the organic parts lie. In the main stem they form a continuous 

 fascicle (see fig. 18) which at the basis gradually resolves itself into thinner and thinner 

 fascicles (see tig. 23) continued through the branched roots into which the stem divides itself. 

 At the base of these roots the spicula are still surrounded by an exterior organic stratum; 

 but this soon disappears entirely; and the exterior ramifications are formed exclusively by 

 the spicula themselves, the fascicles of which continue branching, becoming at the same time 

 thinner and thinner, until the last ramifications only consist of 2 single rows, in which the 

 spicula are arranged, not side by side but alternating, and so that the ends of the spicula in 

 each row lap over each other, or wedge themselves in between the preceding ones in the 

 same row and the corresponding ones in the second row (see fig. 24) ; each of these terminal 

 ramifications ends, when in a perfect (uninjured) state, in one single spiculum. 



From the fascicle of spicula in the main stem, there issue in the side-branches similar 

 fascicles, the innermost spicula of which are wedged with their extremities in between the 

 spicula of the main stem. Also in the numerous tapered processes which are arranged cir- 



