692 
Proceedings of the Royal Society 
Monday , ls£ April 1872. 
Professor Sir BOBERT CHRISTISON, Bart., President, 
in the Chair. 
The following Communications were read : — 
1. On Cardiocarpon. By Professor Duns, D.D., F.R.S.E., 
New College. 
The attention of the Society was called to many beautiful speci- 
mens of Sphenopteris laid on the table. These had been obtained 
by Dr Duns and his predecessor, Dr Fleming, from the old work- 
ings in the Burdiehouse limestones, near Edinburgh, well known 
from Hibbert’s Memoir (1835), and from the papers of more recent 
observers. The species exhibited were chiefly S. artemisicefolia 
and S. affinis. An Antholite (A. Pitcairniae) was also shown, in 
which the pedicels that spring from the flower-like buds in the 
axils of the bracts, sub-opposite in the spike, are well represented. 
The author then referred to Cardiocarpon, Brong., and to the 
species named by Brongniart, Bindley, and Hutton, and more 
recently by Dawson and Lesquereux. It was pointed out, that 
very many Cardiocarpa occur in association with the specimens of 
Sphenopteris on the table. On three of these alone there are 
above 160. Of these, some are almost globular, others are oval. 
Some taper to a single sharp point ; others, and the majority, have 
an acute bifid apex. In many the medial ridge is not seen, in 
others it is highly marked. In a few this ridge has an excurrent 
appearance, both at the apex and at the supposed point of attach- 
ment to the plant. Many of the forms are so placed as to present 
an appearance of organic connection with the Sphenopterides. The 
author then showed that it “ is needful to guard against a tendency 
to give undue importance to the mere fact of association. If in 
other departments this has lead to most erroneous inferences, it 
will he sure to mislead in the study of pakeobotany. Some weight 
is, no doubt, to be given to the fact, but to use it to any extent as 
a guide in determining the affinities of fossil plants is, to say the 
least, not safe. Principal Dawson has pointed to the occurrence 
