ZOOLO&Y OF FERNANDO NORONHA. 
587 
projecting from a common cavity. Colour white. Entire speci- 
men about an inch long, and f of an inch in diameter (lxf xf 
inch) ; broken out on one side, if not the point of attachment. 
The uppermost or principal division ending in a peristomatous 
mouth, which can only he seen with a microscope, hence to the 
unassisted eye looks “ naked ” ; in. in diameter. The same 
on the summit of each inflation, hut reduced to the size of a pin’s 
head. Surface of the body smooth, composed of intercrossing 
arms of quadriradiate spicules only, between which are the pores. 
Vents as just described, leading into a general eloacal cavity 
corresponding in its inflations with those of the body. Surface 
of the cloaca scattered over with holes of very different sizes, 
very irregularly situated in a layer of minute quadriradiates 
whose fourth arm is much smaller than the rest, curved towards 
the oral orifice and projecting plentifully above the surface of 
the cloaca. The spicules of three kinds, viz. 3-radiate, 4- 
radiate, and linear cylindrical acerate. 
Wall of the body about y 1 ^ in. in diameter, composed of 
three layers of spicules, viz. : — 1, consisting of comparatively large 
qua'driradiates whose shaft projects inwards and whose other 
three arms are spread out horizontally over the surface; arm 
about - 4 ] y by y-jLy in. in its greatest diameters ; 2 (the middle 
substance of the wall), consisting of 3- and 4-radiates mixed 
irregularly, whose arms are about the same size as that of the 
quadriradiates of the first or external layer ; 3, or internal 
layer, forming the surface of the cloaca, and consisting of minute 
or infinitely smaller quadriradiates, whose shafts are directed 
outwards ; the other two arms horizontal, and the fourth, or 
“ spine ” as it has been called, which is much the smallest, pro- 
jecting above the surface in the way mentioned. Peristome con- 
sisting of palisading spicules about yj-y in. long, very fine and 
straight with abruptly pointed ends', crossed and kept in position 
by the spreading arms of the quadriradiates of the third, or eloacal, 
layer, here much enlarged. Wall permeated by branched canals, 
which commencing on the pores on the surface end in the holes or 
apertures on that of the cloaca. 
Loc. Island of Eernando Noronha. 
39. GrEODiA. — Fragments of skin and body-substance. Same 
as No. 11, &c. 
