BY R. ETHERIDGE, JUN. 159 



Genus Lamna, Cuvier, 1817. 

 (Regne Animal, torn. II., p. 126.) 



Lamna Daviesii, sp. nov. 



Sp. Char. — Vertebrae four inches high, three-quarters of an inch 

 in length, and with a transverse diameter of more than two 

 inches. Outline of the centrums oval, with a slightly concave 

 surface. Peripheral fissures very narrow and numerous, margins 

 of the centrums prominent and rounded. 



Obs. — The present very remarkable specimen consists of seven 

 vertebrae of a Selachian fish, firmly united together, but slightly 

 displaced obliquely from their normal position, and as a whole 

 six inches in length. In all probability, from the difference in 

 the height and transverse measurement, these vertebrae had to 

 some extent an oval outline, but this may have been intensified 

 by the oblique displacement they have undergone. 



With our present unsatisfactory knowledge of the remains of 

 this group of fish in bygone periods, it is difficult to decide on a 

 genus for these remains, but there is a general correspondence to 

 the excellent figures given by Agassiz of the vertebrae of extinct 

 species of Lamna* for it is quite clear that the whole of each 

 centrum was ossified, as in the family represented by the genus 

 in question. According to Agassiz's statement as to the number 

 of the peripheral fissures in the anterior, posterior, and abdominal 

 regions of the column, the present specimen would be those of the 

 abdominal. 



It must be the representative of a very large fish. The Aus- 

 tralian Museum contains a CarcJmrodon Rondeletii, about nine 

 feet long, with vertebrae the centrums of which are about half 

 the size only of those in this fossil. Judging by these measure- 

 ments, it would appear to Mr. J. Douglas-Ogilby, who has kindly 

 gone into the question with me, and myself, that we have here 

 the remains of a fish which must have been at least from 18 to 20 

 feet long. 



* Loc. cit. t. 40b- f. 16-20. 



