Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 411 



These specimens, and others, have since been studied by R. Lawley, and the 

 results of his investigations have shown that the species is the same as C. rondeletii, 

 M. & H., which still exists in the tropical seas. Smith Woodward has ac- 

 cepted the views held by Lawley, and regards tbe Italian fossil fish remains as 

 pertaining to the existing species. Should all these determinations prove correct, 

 the occurrence of a representative of the existing species in the Chalk of Faxe will 

 be interesting. 



Formation and Locality. — Etage Danien (Nyera Kridt) : Faxe. 

 Ex coll. — Mineralogical Museum, University of Copenhagen. 



Grenus. Corax. Agassiz. 1843. "Eech. sur les Poiss. Foss.," vol. iii., p. 224. 



Known only by the teeth, and confined to the Cretaceous rocks. Small or 

 medium size ; compressed, and more or less triangular ; mature specimens 

 generally with uniform marginal serrations ; in young examples the serrated edge 

 is sometimes wanting. Root large, slightly hollow beneath. 



They resemble to some extent the teeth of Galeus and Galeocerdo ; but Agassiz 

 has pointed out that they are readily distinguished by the microscopical structure 

 of the teeth ("Poiss. Foss.," vol. iii., p. 224), which in this genus are solid, as in 

 the Lamnidss ; whilst the teeth of Galeocerdo and Galeus agree with tlie remain- 

 ing Carchariidai in being hollow in the interior. Corax is readily distinguished 

 from Galeus by the smooth anterior margin of the teeth of the latter ; and those 

 of Galeocerdo are very strongly crenulated on the basal extremity, whilst the 

 serrations of the crown are comparatively feeble. The solidity of the structure of 

 the teeth of Corax recalled to Agassiz the similarity to Notidanus, and M. Sauvage 

 (" Biblioth. de I'Ecole des Hautes Etudes," vol. v., No. ix., p. 39), after considering 

 the superficial and microscopical relationship of Corax with Galeus and Notidanus 

 was disposed to consider that structure was of greater importance than external 

 form, and that, in a truly natural classification, Corax will be found to have a 

 greater affinity with Notidanus. Corax, so far as is known, became extinct with 

 th.e Cretaceous period, and it remains to be seen whether its descendants must 

 be looked for amongst the Tertiary and existing Galeus and Galeocerdo or in the 

 Notidanidse. 



TEANS. EOT. DTTBL. SOC. N.S. VOL. IV., PARI VI. 3 N 



