94 







two closely approximated oval fenestrre which lead to the cartilaginous capsules of the organs 

 of hearing : they are covered by the skin in the recent fish. The hyoid arch is suspended 

 from the ends of the tympanic pedicles, behind the lower jaw. The jaws exhibit the modifi- 

 cations of form, the numerous rows, and the mode of succession, of the teeth. 



Hunterian. 



409. A centrum, or vertebral body, of a Blue Shark (Carcharias fflaucus). 



The intervening ossification between the articular cones has obliterated all the vacuities 

 except the two marked (n) which supported the neurapophyses, and the two marked (p) 

 which supported the parapophyses, and which continue to be filled with clear cartilage in the 

 recent vertebra. 



Presented by Prof. Owen, F.R.S. 



410. A series of vertebral bodies of the same species of Carcharias. Mm. Brit. 



411. A series of vertebral bodies of the same species of Carcharias, showing the 



dried remains of the cartilage in the neural and ha3mal vacuities. Mus. Brit. 



412. A series of the bodies of the caudal vertebras of the same species of Car- 



charias. Mus. Brit. 



413. A series of seven vertebral bodies of a larger species of a Blue Shark (Car- 



charias vorax). One of these has been vertically bisected, showing the com- 

 pact but somewhat coarse osseous texture, which fills the interspaces between 

 the terminal articular cones and between the neural and haemal vacuities. No 

 distinct concentric cylinders nor longitudinal plates are present in these ossified 

 parts. Presented by Prof. Owen, F.R.S. 



414. One of the teeth of a large Blue Shark (Carcharias vorax). It is from the jaws 

 of a specimen which measured twenty -five feet in length. One of the fossil 

 teeth of an extinct species (Carcharias meyalodon) is preserved with it. 



Hunterian. 



415. The jaws of a Shark (Carcharias vorax), which show that the teeth of the 



outer row have the crown usually broken off before the base is shed. 



. Brit, 



