Dr. R. H. Traquair—Fish-Remains from Borough Lee. 548 
on the sides of the spine, their slight curvature also ceases, and the 
tuberculation of the anterior aspect gives way to simple undulation. 
Finally, at the point, all ornamentation becomes completely worn off. 
As I know of no other species of Gyracanthus with which the 
present can be confounded, I propose for it the specific name of 
nobilis. It must have attained a very large size—fragments oc- 
casionally indicate a length of two feet or more. 
Gyracanthus Youngi, n.sp. 
Spines attaining a length of probably two feet: usualiy displaying 
gentle curvatures both antero-posterior and lateral. Ridges of 
sculptured portion so litile oblique as to be nearly transverse, though 
beyond the middle of the spine they become somewhat sigmoidal 
in their direction, turning towards the apex above, towards the 
base below. Only towards the apex have the ridges any marked 
obliquity in their middle portions, and they are closely tuberculated 
over their whole extent, excepting towards the apex, where 
occasionally the tuberculation becomes irregular. The groove on 
the posterior surface is less prominently marked, and the lip or 
ridge on the medial or concave side of the spine not so prominent 
as in other species: usually the floor of the groove is covered 
with tubercles at its commencement, where the sulcus closes. 
Medial edge on lip of posterior groove often denticulated, denticles 
sometimes also seen on the outer lip. 
I first observed a fragment of this spine from Bo’ness, in the 
Collection of Mr. Mowbray Cadell; subsequently I have seen it 
from Borough Lee, Cowdenbeith in Fife, Possil in Lanarkshire 
(Collection of Mr. J. Young), Dalry in Ayrshire (Collection of Mr. 
R. Craig). All these specimens are from ironstone of Carboniferous 
Limestone age. In proposing a name for this undoubted new spine, 
T beg to call it after my friend Mr. John Young, of the Hunterian 
Museum, Glasgow, who has done so much for the elucidation of the 
paleontology of the West of Scotland. 
Ctenodus obliquus, var. quinquecostatus. 
In the first of the present series of communications, I mentioned 
a fragmentary specimen of a tooth of Ctenodus, which so far as could 
be seen had some resemblance to C. obliquus, Hancock and Atthey. 
Since that time I have got together a considerable number of more 
perfect examples, which seem to show that the tooth is at least to 
a certain extent new. 
Palatal teeth of this species are more frequently found than 
mandibular ones, and are usually attached to a palatopterygoid bone 
of the usual form. The tooth itself is narrow, elliptical in shape, 
its breadth being rather less than half the length. The inner margin 
is bluntly angulated, arched, sometimes simply arched; from the 
angle (or a point corresponding to it), which is placed behind the 
middle, radiate five stout ridges, of which the inner and anterior is 
the longest, the others rapidly diminishing in succession from within 
outwards, and before backwards: the number five is very constant, 
