Geological Society. 159 
PROCEEDINGS OF LEARNED SOCIETIES. 
GEOLOGICAL SOCIETY. 
February 6th, 1901.—J. J. H. Teall, Esq., M.A., F.R.S., 
President, in the Chair. 
The following communication was read ;— 
‘On the Structure and Affinities of the Rhextic Plant Naiadita’ 
By Miss Igerna B. J. Sollas, B.Sc., Newnham College, Cambridge. 
This plant, the remains of which are found in Gloucestershire, 
was considered to be a monocotyledon by Buckman, but a moss by 
Starkie Gardner. Material supplied by Mr. Seward and Mr. Wickes 
has given the Authoress ground for the belief that Naiadita is an 
aquatic lycopod, and that it is the earliest recorded example of a 
fossil member of the Lycopodiacee, resembling in proportions and 
outward morphology the existing representatives of the group. 
The specimens described show stems, leaves, and sporangia which 
appear to be borne laterally on the stem and to be embraced by the 
bases of the leaves. Stomata do not appear to occur, and the 
association of leaves of different types leads to the conclusion that 
the three described species are in reality but one. The stems 
consist mainly of long, thin-walled tubes covered with an epidermis 
of long rectangular cells; the leaves, in vertical section, show 
only a single layer of complete cells. The absence of stomata 
and cortical tissue may be explained, if the plant was submerged 
when living; but it is possible that the lower tissues of the leaf are 
lost, together with any stomata which may have been present. 
May 22nd, 1901.—J. J. H. Teall, Esq., M.A., F.R.S., 
President, in the Chair. 
. 
Mr. Groner Assorr, in exhibiting some specimens of Cellular 
Limestone from the Permian beds at Fulwell, Sunderland, 
which he proposed to present to the British Museum (N atural 
History), remarked that their interest depended upon the assumption 
that they were entirely inorganic. Although showing a remarkable 
resemblance to corals, yet no zoologist or geologist had yet claimed 
them as organic. If this surmise were correct, the carbonate-of- 
lime-molecules—probably when amorphous—must have had some 
inherent molecular directive force which produced the 
numerous distinct patterns in their structure. These fall into 
four distinct classes :—-honeycomh (two kinds), coralloid, and 
pseudo-organic, the last-named being remarkable for having 
a constant discoidal shape, and therefore those of this class must 
have had their external form also controlled by the hypothecated 
force. Each class appears to have passed through four stages of 
