158 Mr. H. J. Carter on Grantia ciliata, 
slightly curved, fusiform, sharp-pointed acerates, about as 
long as the collar is broad (fig. 2, 2), arranged longitudinally 
side by side, with their convexities inwards, and supported 
inside by a layer of tri- and quadriradiate spicules con- 
tinuous with that of the surface of the cloaca, and equally 
armed by the projecting spur of the quadriradiate, although 
of course deficient in the holes of the radial chambers, which 
cease at the commencement of the structure externally and 
internally. ‘ Crown” consisting of a circular row of long, 
straight, smooth, almost cylindrical spicules, about 1-18th inch 
in length, arranged longitudinally side by side, tapering 
slightly towards their free extremities from an equally slightly 
enlarged and pointed end which penetrates for some distance 
the distal margin of the collar, and on issuing thus forms a 
fringe or pencil of setaceous spicules that, when together, pre- 
sent the asbestine sheen above noticed, and, finally, may beex- | 
panded or approximated as required. Internal or body- 
structure (fig. 2, ee) composed of radiating prismatic chambers 
in juxtaposition, which extend transversely from the conuli that 
form their extremities on the surface to that of the plane of the 
cloaca internally (fig. 2, £7), supported throughout by the inter- 
lacing of tri- and quadriradiate spicules, which are so disposed 
in their courseas to present a hexagonal form separated by small 
triangular interspaces externally (fig. 2,dd), and on the surface 
of the cloaca, so as to leave a number of holes corresponding in 
regularity to the chambers of the body (fig. 2, m), each of which 
is provided with a sphinctral diaphragm of sarcode just inside 
the margin (fig. 6,). Stem (fig. 2, 7) very variable in length, 
often obsolete, composed of a solid cylindrical mass of the 
tri-, quadriradiate, and linear spicules above mentioned, ex- 
tending from the bottom ofthe cloaca to the object on which 
the sponge may be growing, and, of course, as destitute of 
the conuli and the radial chambers as the collar of the peri- 
stome. Root (fig. 2, 4) presenting a group of tri- and quadri- 
radiate spicules, from each of which an arm of variable length, 
below 1-60th of an inch, is considerably extended backwards 
and longitudinally, tapering at first and then ending in a more 
or less inflated lanciform extremity ; surrounded by a fringe 
of short and long spiniferous or toothed spicules recurved or 
directed backwards, such as have been described under nos. 3, 
5, and 6, most of which, but especially the latter (whose 
proximal ends are more or less lanceolately inflated, their 
length greater, and their teeth larger than those about the 
body), have their extremities fixed in their own or the indu- 
rated sarcode of some other neighbouring organism, which ad- 
heres to the rock (fig. 8) and thus forms the ‘‘ root” or final 
