remarkable Species of Cliona. ae) 
of the goad-like or first kind of spicules, which are packed 
closely together side by side, normal to the walls they form 
(fig. 14)—their globular heads forming the exterior (fig. 15), 
and their mucronate ends the interior surface of the dia- 
phragms. The interstices between the spicules filled with 
a tough brownish-coloured kerataceous cement, A number of 
both the goad-like and the slender pin-like spicules lie on the 
outer surface of the diaphragms, some taking a circumferential 
and others a longitudinal direction; in the case of the disk- 
like and imperforate conical forms, these radiating superficial 
spicules form a wisp-like cap (fig. 9) over the apex or the 
centre as the case may be, over which also their points meet 
and cross one another, while their heads are turned towards 
the circumferential edge. A few of the minute flesh-spicules 
occur along with the others; and thus the spiculation of the 
diaphragms is as complete as that of the sponge. 
The diaphragms have a constant thickness, viz, that of the 
leneth of the goad-like spicules; but they vary in diameter 
according to the size of the aperture they fill, 
Habitat. In the calcareous skeleton of Jsis, sp, (Deciduous 
specimen.) 
Locality. (?) 
Remarks, In examining the débris from a specimen of Js?s, 
sp-, which I had broken to pieces for another purpose, I came 
across one of the singular mucronate spicules which form the 
staple spicule of this sponge ; and taking it to belong to some 
unknown member of the Suberitide, I set to work to discover 
the organism from which it had been derived. I then found 
certain curious patelliform bodies (the diaphragms already 
described), which on examination proved to be mainly com- 
posed of this kind of spicule; but since these bodies were 
wholly unlike any sort of sponge with which I was acquainted, 
I concluded that they were wanting in some of their parts, 
and continued my search in the hope of discovering one more 
perfect than the rest; then I met with them, 7m sctw, in the 
chambers of our Cliona, to which they evidently belonged. 
Now arose a question as to their real relations to this sponge. 
And here only two alternatives presented themselves to my 
mind: either they were in some way connected with its pro- 
pagation, embryos or “ seed bodies ;” or else they performed 
the office of septa or diaphragms. But the only known 
method of propagation amongst the Clionide is by means of 
ova, which they produce plentifully, giving rise to ellipsoidal 
gastrule provided with all the forms of spicule proper to the 
adult sponge. Thus the possession of a full complement of 
spicules is a character common to the bodies under considera- 
