56 Transactions. 
centre, continuing beyond the distal extremity. To this stipe 
are attached, at an angle of 30 degrees, the cellules, which are 
beautifully ornamented with a kind of lace or network placed 
around them from the outer margin to about half way on each 
side of the solid axis; the other two halves on the two.sides of 
the stipe being filled in with a kind of hairy, irregular network. 
The cells at the outer edge are of a finely rounded or convex 
shape, numbering about 26 to an inch, and are alternate on 
opposite sides of the frond, while they gradually diminish from 
three-quarters of its length to a lancet-shaped point. I think 
there can be no doubt that there was a chitinous covering over 
the fine hairy netting for protection that has been worn ee ‘ 
Locality—Hartfell and Dobb’s Linn. 
Genus Dicranograptus (Hall), species ramosus.—The polypery 
towards the proximal paint has a double row of cells, but divides 
or bifurcates at a certain length up into two monoprionidian 
branches on the outside only, or the polypery keeps the same 
line as commenced at the proximal points, and has two small 
lateral spines at each side of a minute radical. The structure of 
Dicranograptus ramosus (Hall) resembles the form of Diplograptus 
for so far up, but the hydrothece appear to have the same form 
and structure as Climacograptus. The branching off of the two 
arms at a certain distance up make it easily distinguishable from 
the other allied forms—Dziplograptus and Climacograptus. The 
genus Dicranograptus, as far as known, is entirely confined to 
the upper Llandeilo rocks of Britain at present, but it is found 
in the Cardaoc rocks in North America. Locality—Hartfell and 
Dobb’s Linn. 
Genus Plewrograptus (Prov.)—This large and rather remarkable 
Graptolite which we now take up is one of the branching forms, 
and is, perhaps, one of the most curious of any of our British 
forms, and seems to have some small- resemblance to. the Plewro- 
graptus, as figured by Mr Carruthers, or nearly related thereto. 
Mr Carruthers had first given it the name of Cladograptis linearis. 
The Generic name is one that was proposed by Genitz, but Mr 
Carruthers, not seeing it to be appropriate, then changed it to 
Dendrograptus linearis. It is now recognised as Plewrograptus 
linearis. The frond is composed of two long serrated branches 
springing from a radical or initial point, and gives off branches 
at certain distances and mostly at right angles to the main stems. 
I have specimens with a third re-branching process given off, 
