SHOWING STRUCTURE, FROM THE RHYNIE CHERT BED, ABERDEENSHIRE. 879 
cross-section. The specimen is incomplete on the upper side in the figure, but shows 
all the essential parts. Centrally is the outline of the main axis with a diameter of 
140 m. This is clothed by a zone of small cells, in relation to which the bases of a 
number of branches can be seen. 
It is tempting to recognise in these specimens parts of small axes with a con- 
struction like the existing Characete. This is not improbably their nature, but some 
suspension of judgment is perhaps desirable until further specimens are found. This 
also applies to another specimen represented from Mr Cran’s drawing in text-fig. 5. 
It may perhaps be the longitudinal section of a node similar to those in the two 
preceding specimens, but its nature does not appear to us to be sufficiently clear to 
do more than record it. 
Some other remains now to be described were found in Mr Cran’s sections in 
close association with the above specimens, and probably belong to the same organism, 
though there is no direct proof of this. 
The specimen shown in fig. 95 had penetrated, or at least was situated beneath, 
the surface of a decayed stem of Rhynia Givynne-Vaughani. Its structure, which 
is not shown in any one plane of focus, is brought out by Mr Cran’s drawing in text- 
fig. 2. There appears to have been an elongated internodal cell widening out to a 
nodal disc of small cells. The axis possibly continued beyond this, while laterally 
from the nodal disc there arose two wider appendages, one of which was swollen 
distally. We tentatively suggest a comparison of this specimen with the node of a 
Characeous rhizoid which bears bulbils. 
The specimen in fig. 96 may be placed in relation to this. Here the continuity 
of the slender tubular axis of the rhizoid (?) can be traced. The segment above the 
oblique septum bulges out, and appears to have formed several cells. It continues 
into the large globular vesicle (bulbil ?), the distal portion of which is wanting at 
the edge of the section. A shallow nodal disc, probably the basal group of cells in 
optical section, is evident at the base of this vesicle, which we thus tentatively 
interpret as a bulbil attached to a rhizoid. The details of the region of attachment 
of the vesicle are shown in text-fig. 3. 
In fig. 97 a similar globular structure is seen lying free in the matrix of the 
chert. The thickness of the preparation allows it to be viewed as a solid object. 
To the right a node-like disc of cells is attached to the globular vesicle, and from 
some of the cells of this nodal disc slender tubular filaments appear to. have grown 
out. It is possible to regard the vesicle as borne laterally on the filament, but the 
above interpretation seems more probable. In that case the remarkable resemblance 
which the specimen presents to a germinating bulbil of Char a aspera or Lampro- 
thamnus is of interest in considering a group of remains which we appear to be 
forced to compare with Characese. 
In connection with the specimens last described which came from Mr Cran’s 
block, the assemblage of imperfectly preserved remains of uncertain nature shown in 
TRANS. ROY. SOC. EDIN., VOL LII, PART 17 (NO. 33). 135 
