1882-83.] Edinburgh Naturalists' Field Club. 51 



ferred as carpal bones to the shoulder girdle. 2, They referred 

 to the skin certain patches of minute tubercles. 



Turning now to the large fragments from Burgh Lee, we find that 

 there are the remains of two spines, one of them measuring 16 inches 

 in length, the other a mere fragment of 4 inches. They lie with very 

 little post-mortem disturbance. The apices nearly touch in the same 

 plane, the bases are widely divergent, and between them are the re- 

 mains of the carpal bone, so-called, of Messrs Hancock and Atthey. 

 This bone is triangular ; its longest measurement is 6^ inches, 

 its broadest probably 4^ inches : a little bit is broken off from 

 one edge, but it is very nearly perfect. It presents the same 

 appearance of loose texture as seen in the Northumberland speci- 

 mens, and is undoubtedly the same bone. One or two detached 

 bones have likewise occurred to me in the Wardie Shales. It is 

 therefore satisfactory to find this bone so intimately associated 

 with the spines (in a specimen which has undergone scarcely any 

 disturbance), that any doubt lingering in one's mind, caused by the 

 presence of such an extensive ossification in a usually cartilaginous 

 skeleton, has no excuse for being any longer entertained. 



The larger and nearly perfect spine has a short base of attach- 

 ment, and the area of attachment at the back of the spine is not 

 symmetrically divided, but has a greater development on one side 

 than on the other, giving the spine the appearance of being twisted. 

 This, the lateral curvature, I suppose, of Messrs Hancock and 

 Atthey, is evidently due to its being a paired spine. The same 

 specimen, too, is much worn at the apex. The wearing begins 

 3i inches downwards from the broken-off point, passes gradually 

 into a deeply excavated groove, which again passes into a smooth 

 terminating area, from which all traces of ridges and tubercles have 

 disappeared. This wear is, as in the Northumbrian specimens, on 

 the anterior aspect of the spine. 



The evidence is therefore cumulative, that we have here the 

 remains of the pectoral region of a large shark. The two spines 

 are of the species known as Gyracanthus tuberculatus, Ag., and they 

 do not differ from each other in the slightest degree in size or 

 ornament. They are, however, right and left, as was to be expected. 

 A glance at any part of the specimen (in the proper plane) behind 

 the spines, reveals the presence of the dermal tubercles. They are 

 a good deal scattered. Whether they were found on other parts of 

 the animal than the fin is uncertain, though probable. One finds 

 patches of them occasionally with no spines near. They certainly, 

 however, formed a dense coating on the surface of the fins, as a 

 beautiful specimen in my Wardie collection shows. 



At this meeting a series of fossil sections, including transverse 



