Further Notes on Carboniferous Selachii. 425 



shoulder-girdle, or coraco-scapular arch, whose direction is 

 obliquely downwards and forwards. Careful examination 

 reveals no composition out of distinct membrane-bones ; on 

 the other hand, its substance has\in unmistakably granular 

 aspect suggestive of calcified cartilage. No trace of paired 

 fins, pectoral or ventral, is visible. 



Commencing at the head, and passing back nnder 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 examina- 

 tion of a most instructive fragment in the collection of the 

 Geological Survey of Scotland, they can clearly be made out 

 to have had the configuration of hollow rings, through which 

 a scarcely constricted notochord must have passed. Ap- 

 pended to the dorsal aspect of this chain of centra is a series 

 of bodies representing the neural arches and spines. Each 

 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 

 representing fin-rays or radials, of which there are three or 

 four to each neural spine ; they are more slender than the 

 latter, but have the same granular structure. They gradu- 

 ally increase in length towards the posterior third of the 

 body, whence they again fall away towards the end of the 

 tail. The abdominal region extends for If inches behind the 

 bead. No ribs are visible, the termination of the abdomen 

 being marked by the commencement of a series of haemal 

 elements quite similar in configuration and structure to the 

 neural ones above, and these now extend to the extremity of 

 the tail. No fin-rays are seen on the ventral aspect of the 

 skeleton, nor have I seen any trace of any dermal hard 

 parts. 



This is, indeed, one of the strangest fishes as yet yielded 



