98 



434. The centrum of a caudal vertebra of the Made maxima, bisected vertically 



and transversely. 



This is one of the vertebrae of the animal surmised to be a ' Sea-serpent,' which was cast 

 on shore at Stronsa, in the Orkneys, September 1808 : it is described by Dr. Barclay in the 

 ' Wernerian Transactions,' vol. i., who transmitted the vertebra to Sir Everard Home. 



It shows the arrangement of the osseous matter between the two terminal bony cones, 

 which chiefly constitute the vertebral centrum. These cones are united together at their 

 circumference by longitudinal bony plates arranged parallel with the axis of the vertebra : the 

 rest of the intervening space between the cones is occupied by concentric circular plates or 

 cylinders of bone, which are minutely perforated : both the longitudinal and cylindrical plates 

 are interrupted by the neural and haemal conical excavations : these and the intervals of the 

 several plates are filled by clear or hyaline cartilage in the recent fish. 



Presented by Sir Everard Home, Bart., F.R.S. 



435. The terminal osseous cones of a vertebral centrum of the Selache maxima. 



The opposite surfaces of each show at their periphery the converging lines to which the 

 longitudinal plates were attached, and at the rest of their surface the concentric lines to which 

 the progressively decreasing bony cylinders were attached. The smooth articular surfaces of 

 the cones show only concentric lines : ossification has obliterated their originally intercom- 

 municating foramen. 



Presented by Sir Everard Home, Bart., F.R.S. 



436. A longitudinal section of two vertebral centrums of the Selache maxima. 



It shows the coarse irregular osseous texture of the terminal cones, the sides of the peri- 

 pheral longitudinal diverging plates, and the cut edges of the central concentric cylinders. 

 One of the centrums has been bisected transversely, to show more clearly the twofold 

 arrangement of the bony laminae between the terminal cones : also the perforations of the 

 cylindrical plates, and the transition from the concentric to the diverging lamellar structure : 

 the outer cylinder being, as it were, broken up into processes which join the irregular inner 

 edges of the longitudinal plates. 



Presented by Sir Everard Home, Bart., F.R.S. 



437. A longitudinal section of four vertebral centrums of the Selache maxima, show- 

 ing the dried elastic capsules by which the margins of the terminal coijes are 

 joined together. Presented by Sir Everard Home, Bart., F.R.S. 



438. The opposite section of the same vertebrae. 



Presented by Sir Everard Home, Bart., F.R.S. 



