878 DR R. KTDSTON AND PROF. W. H. LANG ON OLD RED SANDSTONE PLANTS 
below. Lastly, at d in fig. 98 there is a thin-walled globular vesicle, unfortunately 
ill-preserved, but apparently attached to a filament. Attention is directed to it, 
since similar structures occur in the neighbourhood of filaments of the Alga in 
several blocks of the chert from different levels in the deposit, and globular vesicles 
are found in the groups of remains described below. 
Traversing the' peaty matrix of the block from which fig. 98 was obtained, several 
examples of structures which we can only interpret as rhizoids were met with. Two 
of them are represented in figs. 103 and 104 and text-figs. 9 and 10. The long 
tubular cells are separated from one another by an oblique septum, the region of 
junction being more or less enlarged. In relation to the septum an irregular node 
of small cells was usually developed (fig. 104). These structures present a general 
resemblance to the peculiar rhizoids of the Characese. Another example is 
represented in text-fig. 11. 
We feel no hesitation as to the vegetable nature of the remains described above, 
nor as to their belonging to an Alga. The simple filaments might be comparable to 
a number of Algse, but the presence of occasional nodal discs and the appearance of 
the rhizoids strongly suggest more special comparison with the Characeae. 
Remains 'provisionally associated with Algites Cranii. 
(PI. VIII, figs. 91-97 ; PI. IX, figs. 105-108.) 
As mentioned above, we received certain remarkable specimens from the Eev. 
W. Cran, B.D., of Skene. These occurred in the cloudy matrix of a loose block of 
the chert containing Rhynia Gwynne-Vaughani and animal remains. 
The first specimen shown to us by Mr Cran consisted of a small axis embedded 
in the matrix of a rather thick section. The thickness had the advantage of -leaving 
the small “ shoot ” intact, but made observation and figuring difficult. The morpho- 
logy of the specimen is well shown in Mr Cran’s drawing reproduced in text-fig. 1. 
This shows an axis formed of four internodal cells separating as many nodes ; these 
are marked by the whorls of more slender and sometimes septate appendages borne 
at each. In relation to, and possibly in continuity with, the upper end of the 
specimen is a peculiar row of cell-like structures ; this is one of the difficulties in the 
interpretation of this specimen. 
The appearance of the specimen is further shown in figs. 91 and 92 on PI. VIII. 
These are magnified 100 diameters, and show the small specimen as it lies in 
the cloudy matrix. The plane of focus in fig. 91 brings out the internodal cells, 
while fig. 92 shows the whorled appendages at the nodes better. A portion of the 
specimen showing the appendages at two of the nodes is more highly magnified in 
fig. 93. 
Another very instructive specimen discovered by Mr Cran is represented on 
PI. VIII, fig. 94, and text-fig. 4. This can be readily placed in relation to the 
preceding specimen as a node with the bases of the verticillate branches as seen in 
