118 Proceedings of the Royal Society of Edinburgh. [Sess. 
the fungi are regarded as belonging to the Phycomycetes. A number of 
form-types are described and illustrated by photographs. Some of the 
most distinct of these forms are given specific names in the comprehensive 
genus Palceomyces. The species distinguished are Palceomyces Gordoni , 
P. Gordoni var. major , P. Aster oxyli, P. Hornece, P. vestita, P. Simpsoni, 
P. agglomerata. The possibility of there being a symbiotic (mycorrhizal) 
relation between certain fungi and the Vascular Cryptogams is discussed ; 
there is no conclusive evidence in favour of this, but the question is left to 
some extent open. The majority of the fungi in the Rhynie peat were 
certainly living as saprophytes. 
Bacteria were doubtless present in abundance, but are difficult to 
distinguish in the granular matrix. The most remarkable representative 
of the Schizophyta is a filamentous organism with the small protoplasts 
preserved. It is named Archceothrix oscillator if or mis and is compared 
with Beggiatoa and Oscillatoria among existing plants. 
Scattered remains of a remarkable Alga, the vegetative structure of 
which presents a number of resemblances to existing Characeee, are 
described under the name Algites ( Palceonitella ) Granii. Two frag- 
ments belonging to an organism with the characteristic structure of 
Nematophyton are described as N. Taiti. The occurrence of this plant 
in such a deposit is noteworthy, and the small specimens are of importance 
in showing the structure of the peripheral region that has not been 
preserved in specimens previously described. 
The succession of the plants throughout a section of the Chert Bed as 
exposed in situ is followed, and the conditions of formation of the Rhynie 
deposit discussed. On grounds mainly of resemblances presented by 
Asteroxylon to Thursophyton ( Lycopodites ) Milleri, the view is expressed 
that the Rhynie Chert band is probably of Middle Old Red Sandstone age. 
(. Issued separately August 23, 1921.) 
