184 MK. T. ATTHtY OX rXEKOPLAX COKNUTA. 



ribs on the piece of slialc ui'e, there can be little doubt, vei-tebrac 

 of Pteroplax. 



Bones of an extremity. — These are figured on Plate XYI. 

 fig. 3, and are only three in number, small and dislocated from 

 their normal relation, but still very near to each other ; they lie 

 BuiTounded by many scutes on a slab of shale eight inches by 

 five inches and a half. They appear to be the terminal bones of 

 a digit, but whether of an anterior or posterior limb is not easy 

 to determine. They diminish in size like digital bones : the 

 biggest is one inch long, and half an inch wide ; the next is 

 shorter and more slender ; the tliird or smallest is pointed at the 

 fui'ther end; with this exception the ends of these bones are 

 concave, and the sides contracted at the middle. 



Scutes. — On the last-mentioned slab, and on its counteri)art 

 measuiing five inches and a half by four inches and a half, are 

 bedded altogether one hundred and four scutes, lying in the same 

 plane, but scattered about without any order; besides these I 

 have only one other scute on a small bit of shale in my collection. 



These scutes vary in size from one to three-quarters of an inch 

 in length ; and from one-sixth of an inch at the anterior end, 

 which is rounded, they taper to a rather sharp point behind . 

 their upper surface on the whole is convex and their under sur- 

 face concave from end to end. On their upper surface is a strong 

 ridge nearer to one margin than the other; the former is the 

 tliicker edge and also the longer, whilst the surface slopes gra- 

 dually to the other side, which is (juitc thin. Two of these 

 scutes are represented in Plate XYI., fig. 2. 



It is presumed that the above are the scutes of Pteroplax, as 

 they arc different in form from the scutes of the two other larger 

 Labyrinthodont Amphibia, and are also much smaller and of more 

 delicate make, and wc know of no other animal-remains in our 

 coal-field to which they could belong. They are from the same 

 pai-t of the mine as the other remains herein noticed, and bear a 

 certain proportion of size to the crania described. 



The small size of these crania, their furm and the smaller num- 

 ber of bones entering into their formation than into those of 



