260 
PROFESSOR W. C. WILLIAMSON ON THE ORGANIZATION 
the elegant Cardiocarpon represented in figs. 129, 130, & 131. It consists of two parts, 
the actual seed and a slender peduncle. The former is about • 4 in length and the latter 
■25, whilst its diameter at its widest point, i. e. near its base, is nearly -2. Eig. 129 
represents the natural size of the specimen; in fig. 130 it is enlarged six diameters. 
It is lanceolate in form ; a prominent ridge which runs up its centre is thick at the 
base, and almost reduced to a line at the apex. On each side of this ridge is a very 
regular, parallel groove, external to which again are two broad elevated surfaces, 
rounded and prominent at the base, but with somewhat flattened surfaces, and which 
extend to the lateral margins of the seed as well as to its apex. The narrow peduncle 
is nearly as long as the seed. 
Owing to the opposite side of this specimen being crushed, I could not obtain a good 
section revealing its internal structure ; but it clearly shows a double membrane, the 
outer one of which, I presume, will correspond with the membrane b in the sections of 
the other Cardiocarpons, and the inner with the perispermic one. Both these mem- 
branes appear to have extended to the apex of the seed. The true testa seems to have 
been a very thin one. 
A second fragment of a slightly larger specimen of the same species, also found by 
Mr. Butterworth, is valuable because it exhibits much of the cellular parenchyma of 
the perisperm. Some of these cells from near the perispermic membrane are repre- 
sented in fig. 131. In this figure, some of the cells nearest the perispermic membrane, 
g, appear loose and detached ; but in a second section which I have obtained they are 
all compactly united as in ordinary parenchyma, and as seen in the lower part of 
fig. 131. Many of these cells have a mean diameter of •006, which is half as large 
again as those of C. anomalum , represented in fig. 120. This Cardiocarpon differs from 
all those of which I can discover any published account. I have therefore given to it 
the name of C. Butterwortlm, as a memorial of the valuable aid which its discoverer 
has rendered me, by supplying me with specimens of the Oldham fossils, as well as by 
his quickness in detecting new forms and his skill in preparing sections of them. 
Figs. 132, 133, & 134 represent three seeds from a slab of shale from Swinehill Col- 
liery, near Stonehouse, Lanarkshire, for which I am indebted to John Young, Esq., of 
the Glasgow Hunterian Museum*. The seeds are scattered over several large slabs of 
shale in great numbers, no two of them being exactly alike, save in the fact that they 
are all compressed, as well as more or less fluted longitudinally. They also exhibit the 
appearance of a surrounding margin ; but I suspect that this may merely have been a 
result of pressure acting upon a thick testa, which would resist that pressure where it 
was folded back upon itself. These seeds appear to me to agree with the figure and 
description given by Dr. Dawson of his Cardiocarpum tenellumf. I scarcely think that 
* Mr. Young informs me that these specimens were discovered by Mr. John Smith, of Stables, Kilwinning, 
in Ayrshire. The coal from the roof of which they were obtained is the Virtue-Well coal, one of the seams of 
the upper series of Coal-measures. 
t ‘ Report on the Fossil Plants of the Lower Carboniferous and Millstone-grit’ Formations of Canada/ pi. vi. 
fig. 50, p. 28. 
