: 
278 PROF. T. M‘K. HUGHES ON SPONGIA PARADOXICA. 
and further, that in the concretion-theory, another possible expla- 
nation has been offered. J am aware that sponges do often perish, 
so as, in the fossil state, to leave nothing but the form to guide us 
as to the whereabouts of the whole or certain portions of the 
organism. In such cases, however, a part of the structure has 
generally been preserved somewhere; but in the case of Spongia 
paradoaica, I cannot find that any structure has ever been seen in 
the bodies referred to under that name, nor can I learn that there 
are sponges known which have the habit and manner of growth of 
the Spongia paradoxica. Therefore it would seem that until those 
familiar with sponges offer some further evidence, we must abolish 
the name which assigns to this body a definite zoological place. 
Through the courtesy of Mr. W. Johnstone, I am allowed to 
append the quantitative analyses of the so-called sponge and sponge- 
bed, which were read to the Society in the discussion upon my paper. 
They fully confirm the results arrived at by Professor Liveing’s ex- 
amination of my specimens. 
ST, IV v 
OF 6 etna ies 53°250 52°050 52-400 
Oe a ranene tee 42-295 41456 ~- 41-283 
MEO Res 0°353 trace 0-477 
PONG Be. 0-289 0°268 0°338 
HELO, cocbacaeceee 0°325 0°635 0:213 
10 ieee tee Ge eee eT trace trace 
11 Mie elie te a 0748 0-778 0°810 
OMe cece ceee trace trace trace 
Nah ee ee trace trace trace 
SOs eich auaaebiace 3170 5°025 5057 
Organic matter . trace trace trace 
100-410 100°207 100-578 
No. IIT. Sponge-bed. 
», LV. Sponge-bed (immediately above red bed). 
»  V. Spongia paradoxica. 
Discussion. 
Dr. J. Gwyn Jerrreys referred to the creation, either through mis- 
take or fraud, of Molluscan genera and species from the gizzard of 
a common Mollusk, as well as from other organisms not belonging to 
the Mollusca. 
Dr. Hicks spoke of the value of analysis in settling the question. 
Mr. W. Johnstone had made an important series of analyses, 
which, by showing about equal quantities of phosphoric acid in the 
matrix and in the supposed fossils, quite bore out the views of the 
author. 
Dr. G. J. Hryoz said that he agreed with Prof. Hughes that it 
was not a sponge, for no sponge-structure could be detected in it. 
The form alone would be no argument against it being a sponge. 
Forms like the S. paradoxica have been found at many other loca- 
lities. The S. saxonicus of Geinitz, from the Quader-sandstone, was 
similar. G6ppert thought it a sea-weed, and Zittel has suggested 
