97 



429. A section of one of the jaws of a Lamna, with three of the vertical or succes- 

 sional rows of teeth. 



The change from the recumbent to the erect petition is more gradual and progressive, and 

 the number of teeth in reaerve is greater, than in the preceding genera. Eight teeth may be 

 counted in one of the row* of the present specimen. 



Prcttnted by Prof. Oven, F.Jt.S. 



Family Alopeciida. 

 480. The dried skin of a Fox Shark (Alopiat fulpet). Hunteria*. 







Genus Selacke. 



The specimen of Basking Shark (Marhe maxima) from which the specimens Xis. 431 to 433, pre- 

 sented by Sir Everard Home, were taken, was a male, caught in fishing nets off Hastings, NoTember 

 13th, 1808. The length of the animal was 30 feet 6 inches. A brief account of its anatomy U given 

 in the ' Philosophical Transactions' for 1809, p. 177. A second example, also a male, was taken on 

 21st November 1810, in the herring nets off Dieppe, and was described by M. de Blaiaville in the 

 'Annales du Museum,' t. xriii. (1811) p. 88. Some of its tissues were the subjects of the able ana- 

 lyses of M. Cherreul, which are detailed in the same rolume. 



' A third specimen of the Basking Shark, from which Nos. 435 to 438 were taken, was captured at 

 Brighton in the year 1812. 



431. A vertebra of a Basking Shark (Selacke maxima). 



It shows the two deep terminal articular concavities characteristic of the class of Fuhes. 

 The sides of the centrum show the margins of the longitudinal bony plates and their inter- 

 spaces, which were filled in the recent fish by hyaline cartilage. The upper surface is exca- 

 vated by two deep conical depressions here partly filled by the dried remains of the denser 

 cartilage which constituted the neural arch. On the under surface are two similar cavities 

 which were dosed by the similarly dense cartilage forming the haemal arch. 



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



432. A similar specimen. Presented by Sir Everard Home, Bart., F.Jt.S. 



433. The centrum of a vertebra of the same Shark, from which the cartilaginous 



neural and haemal arches have been removed, together with some of the lon- 

 gitudinal plates on one side, to show the outermost perforated concentric 

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



