398 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 



Vertebrce of Oxyrhina mantelli, Ag. 

 (PL XXXIX., fig. 14.) 



Examples of vertebrae of Oxyrhina occur at Kojiinge, in the Etage Sdnonien, 

 characterized by the presence of Belemnitella mucronata. The vertebrfe have a 

 diameter of about 0*06 m., and are 0-015 m. in thickness. The anterior and 

 posterior surfaces are deeply biconcave, with the centre pierced. The concave 

 surfaces of the vertebra are marked by a series of concentric rings, giving a more 

 or less corrugated appearance, represented in the figure. 



Formation and Localiiy. — Upper Senonian : Kopinge. 



Ex coll. — Geological Museum of the University of Lund, Sweden. 



Genus. Lamna. CxmsR, " Rfegne Animal," vol. ii., p. 126, 1817 ; Agassiz, L., 

 1843, " Rech. sur les Poiss. Foss.," vol. iii., p. 287. 



Teeth of medium size, elongated, narrow in proportion to the height, sharply 

 pointed, with cutting edge smooth, base expanded, lateral denticles present, 

 usually one pair ; root large and deeply bifurcated. 



The teeth of Lamna may be distinguished from those of Otodus by being 

 rounder and less compressed, and having the lateral cones smaller and pointed. 



Oxyrhina is devoid of lateral denticles, and is thinner and more triangular in 

 outline than Lamna. This latter genus first appears in the Chalk formation, and 

 is still existing. 



Lamna elegans^ Agass. 

 (PI. XL, figs. 11-17.) 



Dentes squali, . . . Beander, G., 1776. " Foss. Hantoniensia," 



pi. IX., figs. 113-114. 

 Lamna elegans, . . . Agassiz, L., 1843. " Poiss. Foss.," vol. iii., 



p. 289, pi. XXXV., figs. 1—5. {non figs. 6, 7); 



pi. XXXVII. a, fig. 50 {non fig. 58). 

 Lamna elegans, . . . Giebel, C. G., 1848. " Fauna der Vorwelt," 



vol. i., p. 359. 



