170 Mr. H. J. Carter on the Position of the 
XX.—Position of the Sponge-spicule in the Spongida 3 and 
Postscript on the Identity of Squamulina scopula with the 
Sponges. By H. J. Carter, F.R.S. &e. 
In the ‘Annals’ for 1870 (vol. vi. pp. 222, 223, pl. xv. figs. 
1-7) Mr. Saville Kent has described and figured, under the 
name of Lhaphidotheca Marshall-Hallii, a remarkable little 
sponge which he found growing on Lophohelia prolifera, in 
590 fathoms, on the coast off Cezimbra, Portugal,in 1870. A 
section of the sponge, which was half an inch in diameter, 
is given in fig. 2 (/.¢.), where a cell of the Lophohelia may 
be observed to form the centre. On account of the character 
of the greater part of the spiculation, Mr. Kent rightly calls 
this little hemispherical sponge an Hsperia; but the remark- 
able part is, that it is faced by a layer of pin-like spicules, 
whose heads, being outwards and in contact with each other, 
form a kind of tessellated armature on the surface, while their 
points mingle with the points of the skeleton-spicules of the 
Esperia within. In the footnote at p. 253 (cb.) Mr. Kent 
very naturally, therefore, questions my statement respecting 
the spicular elements of Sguamulina scopula, viz. that their 
“ slobular heads” being outwards should have satisfied any 
one that this organism was not a sponge, or words to this 
effect (‘Annals,’ 1870, vol. v. p. 312), citing Rhaphidotheca 
Marshall-Hallit, the little sponge to which I have just alluded, 
as affording an instance to the contrary. 
It was not, however, until the latter part of 1877 that I 
had an opportunity of examining a portion of this interesting 
little sponge, which, together with two mounted slides of it, 
was lent to me by my friend Dr. J. Millar, to whom it had 
been given by Mr. Kent. At first sight I was inclined to 
agree with Mr. Kent, and said, ‘ Verily (although a pin-like 
spicule of this form among the Esperiade is a great anomaly) 
here is a sponge with the heads of its spicules outwards, con- 
trary to my assertion that the proper spicules (that is, the 
spicules made by the sponge itself) never have their large ends 
outwards.” Still this, as will presently be seen, was only a 
prima facie opinion ; for when | came to examine microscopi- 
cally what Dr. Millar had lent me, much was found to modify 
these views, since, in addition to the spiculation of the Hs- 
perta (viz.:—1, a sub-pinlike, staple skeleton-spicule, radiating 
from the centre in branched bundles; 2, a smaller acerate one, 
curved and binding together the points of the latter towards 
the surface ; 3, an inequianchorate, single and in rosette-like 
groups; 4, a bihamate (fibula); and 5, the sheaf-shaped bundles 
of minute acerates, looking like sawdust by reflected light), 
