Dr, R. H. Traquair—Carboniferous Selachit. 1038 
Pristicladodus, M‘Coy. 
There can be no doubt that the specimen from Armagh, in the 
British Museum, to which Mr. J. W. Davis has given the name of 
Carcharopsis Colei, is nothing else than a specimen of Pristicladodus 
dentatus, M‘Coy, with the base broken off. 
Chondrenchelys problematica, n. gen. & sp. 
Among the fishes from the Eskdale beds, obtained from Mr. 
Damon for the Edinburgh Museum, is one whose nature is still 
more problematical than that of Tarrasius, which it somewhat 
resembles in external shape. Two specimens in the Hdinburgh 
Museum have the head and the tail preserved up to near the termina- 
tion of the latter, and of these the lengths are, respectively, 43 and 
7 inches. The shape of the body is singularly elongated and eel- 
like, the head being small, less than 4 of the total length, while a 
long, low, continuous dorsal fin runs along the back from not far 
behind the head to the end of the slender pointed tail. 
In the larger of these two specimens no structure can be made out 
in the head at all, owing to the obstinacy with which a layer of 
matrix adheres to the surface. 
The smaller affords not much more light as to this part, though 
the shape of the head appears pointed, and there is some appearance 
of what is either a mandible or a palato-quadrate arch. It is even 
difficult to make out whether the substance exhibited be true bone, 
or calcified cartilage, though there is a spicular-looking body lying 
longitudinally in the middle of the head, which from its smooth, 
almost glistening, aspect reminds us of bone. About + inch behind 
the head, and apparently not at all attached to it, is an evident 
shoulder-girdle, or coraco-scapular arch, whose direction is obliquely 
downwards and forwards. Careful examination reveals no composi- 
tion out of distinct membrane-bones ; on the other hand, its substance 
has an unmistakeably granular aspect suggestive of calcified cartilage. 
No trace of paired fins, pectoral or ventral, is visible. 
Commencing at the head, and passing back under the aforesaid 
shoulder-girdle to the extremity of the tail is a well-marked vertebral 
column. Here the axis consists of undoubted centra, which are 
rather higher than long. They are crushed and flattened laterally, but 
on careful examination of a most instructive fragment in the collec- 
tion of the Geological Survey of Scotland, they can clearly be made 
out to have had the configuration of thin-walled hollow rings, through 
which a scarcely constricted notochord must have passed. Appended 
to the dorsal aspect of this chain of centra is a series of bodies 
representing the neural arches and spines. Lach of these is short, 
slender, and rod-like, bifurcating below and pointed above, and 
there seems to be one for each centrum. They are not composed of 
ordinary bone, but of small granules placed end to end like a string 
of beads, and that they had not the rigidity of bone is seen from the 
flexuosities which they often present in their contour. Commencing 
almost immediately behind the shoulder-girdle, and appended to the 
neural spines above, is a second series of rod-like bodies represent- 
