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



Odontasjns faxensis, Davis. 

 (PL XXXVIII., fig. 26.) 



Teeth small; the crowns of the anterior teeth on their external surfaces attain- 

 ing a height of O'Ol m. ; erect, acuminate. External coronal surface convex and 

 smooth ; internal one still more convex and also smooth ; very slight ridge 

 along each lateral margin. Base of crown expands laterally to a width of 

 0*012 m., and supports on each side a series of tkree denticles, decreasing in size 

 as they recede from the principal cone ; the denticles are short, conical, and 

 sharply -pointed. The base of the crown is concave. The root is short, with a 

 spongy structure, conforming in outline to that of the base of the crown. 



This form is distinct from any other observed in the Cretaceous rocks of 

 Sweden and Denmark. It, perhaps, most closely approaches Odontaspis acuta, 

 Davis ; but in that species there does not appear to be more than two lateral 

 denticles, the second being much inferior in size to the first. In this sjDecies there 

 are three lateral denticles on each side ; all robust and distinct, and diminishing 

 gradually in size from the centre. 



Formation and Locality. — Etage Danien : Faxe. 



Ex coll. — Mineralogical Museum, Copenhagen University. 



Odontaspis kopingensis, Davis. 

 (PI. XXXVIII., figs. 27, 28.) 



Teeth strong and robust ; crown attains a height of 0*015 m. ; on the median 

 line, conical and pointed ; external surface very slightly convex, smooth ; internal 

 surface deeply convex, rendering the crown very thick and strong. The base of 

 the crown is curved upwards transversely, slightly on the external face, deeply on 

 the internal ; it is 0*01o m. across. A single pair of lateral denticles are present. 

 They are triangular, and the apex of each is pointed. The root is large, deeply 

 forked ; the prongs well advanced on the external face ; and the median part very 

 prominent on the internal one. 



The teeth comprised in this species appear to be rare ; a single specimen 

 occurs in the Riksmuseum at Stockholm from Saltholm, and another in the 

 Geological Museum of the University of Lund from Kopinge. It most nearly 

 approaches Odontaspis acuta, Davis, in general appeai'ance ; but the triangular and 

 somewhat blunt character of the lateral denticles extending at right angles from 

 the crown, are very different from the slender acuminate denticles, curving 

 inwards towards the crown, of Odontaspis acuta. In this species there is no trace 



