PROF. T. M‘K. HUGHES ON SPONGTA PARADOXICA. 275 
plained by supposing it originally a coral reef, and its interstices 
filled with cretaceous mud; it is about eighteen inches in thickness, 
and contains very few organic remains.” He remarks in a footnote 
that “a nearly corresponding bed composed of ramose zoophytes oc- 
curs in Sussex: vide Geology of §.-E. of England, p. 384, note d.” 
The name only is handed on by subsequent writers. So few 
exact observations have been recorded in favour of the fossil being 
a sponge, that we may fairly reconsider the question; and in doing 
so, I am led to go further and question whether the object can be 
referred to any organism. 
The beds in which this fossil is most abundant are full of frag- 
ments of shells, corals, Bryozoa, sponges, &c., and, therefore, spicules 
and other indications of sponge-structure may be seen in any part 
of the mass, just as fragments of any other organism may be found 
where such remains have not been obliterated by chemical action. 
But I cannot find in the specimens which I have had cut, any struc- 
ture associated with or limited by the boundaries of the trailing 
objects known as Spongia paradoaica, in such a manner as to 
suggest that it represents an original organism of the form of the 
paradoxical body in question. Jor fear this might be due to the 
accident of my having less well-preserved specimens, I have asked 
many friends who have had opportunities of examining these fossils, 
whether they have ever seen any structure belonging to the bodies 
in question. The Rev. O. Fisher, of Harlton, replies—‘“‘I have a 
section, by Cuttell, of what I believe is Spongia paradoxica. It 
does not show any structure that I can see. The mode in which it 
ramifies over the rock in a network is very curious. ‘The piece from 
which my slice was cut had a very definite body surrounded by a 
coating of indurated chalk.” 
Next, as to the manner of occurrence of the fossil: it is found in 
beds full of large fragments of Jnoceramus and other fossils, which 
have drifted into their present position; and this, as Mr. Starkie 
Gardner remarked to me on the ground, points to conditions un- 
suitable for the growth of aslendersponge. Many of the undoubted 
sponges, Bryozoa, &c., are fragmentary and apparently transported 
to their present position, while the Spongia paradoxica does not, so 
far as I have observed, ever occur in a fragmentary condition, but 
always forms part of an apparently complete ramifying body. The 
interrupted fragmentary appearance sometimes seen in the face of 
the cliff is due to the breaking away of portions of the cylindrical 
body after exposure of the rock-surface, or to its running into the 
mass so as to be lost to sight, because the irregular fossil does 
not all lie in the plane of the section. It occurs most commonly 
in layers along the bedding-planes, but very frequently extends 
up through the whole thickness of what we may call a bed, 7... 
about 5 or 6 inches, and runs on into the masses which appear 
to belong to the layer above. Now it is very improbable that 
it could support this long trailing stem in a vertical or oblique 
position, or that it grew on while the chalky mud was accumu- 
lating around the lower part, while the form does not support 
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