REMARKS ON SOME CURIOUS SPONGES. 21 
the Academy. It is represented in the accompanying figure 
(Fig. 10), one-half the natural size. The body of the 
sponge is oblong ovoidal, with one side more protuberant than 
the other. The narrower extremity, which I suppose to be 
the upper, is conical, and its truncated apex presents a single, 
circular orifice, the third of an inch in diameter. The oppo- 
site extremity is rather cylindrical with a broad, slightly 
rounded extremity, from which project nu- wig 20. 
merous fascicles of silicious threads. 
The sponge body is of a light brown hue, 
and rigid to the feel. Its surface exhibits 
an intricate interlacement 
of the sponge tissue, which 
appears mainly composed 
of stellate, silicious spic- 
ules of various sizes. The 
coarser spicules of the sur- 
face, of which one is rep- 
resented in Fig. 11, three 
times the diameter of na- 
ture, have five rays. Four 
of these together are ir- 
regularly cruciform, while 
the fifth projects in a di- | 
rection opposed to all the 
others. They appear to 
be so arranged that the crucial rays interlace 
with those of the contiguous spicules, form- 
ing a lattice work on the surface of the 
sponge, while the odd ray opposed to the others penetrates 
the interior of the sponge. ‘The finer tissue, seen through 
the intervals of the latticed arrangement on the surface of 
the sponge, appears to be made up in the same manner of 
finer stellate spicules. Some of the largest stellate spicules 
of the surface have a spread of half an ineh. 
The fascicles of silicious threads projecting from the body 
Fig. 11, 
