Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 365 



Myliobatis. The Asterospondylic sharks occur in very large numbers, and 

 represent several genera. Beautifully preserved specimens of Notidanus, Sca- 

 panorhynchus (Rhinognathus), Odontaspis, Osyrhina, Otodus, Lamna, and Coras 

 are abundant, and have a wide vertical range. The teeth here described as 

 Oxyrhina lundgreni possess peculiarities which, in some respects, dissociate them 

 from Oxyrhina, and it may be found necessary to form them into a new genus. 

 The character and extent of the Selachian fauna indicates conditions very similar 

 to those accompanying the deposition of the EngHsh and French chalk and that 

 of Central Europe generally, whilst it affords comparatively little data for 

 comparison with that of Lebanon. The occurrence of numerous teeth of 

 Scapanorhynchus in the Swedish area is worthy of note, but the fish are not found 

 preserved bodily as they are in the Lebanon chalk. 



The classification adopted is based, as far as possible, on that of the recently- 

 published " Catalogue of the Fossil Fishes in the British Museum (Natm-al 

 History), Part I.," by Mr. A. Smith Woodward. Whilst recognising the great 

 merits of this work, and the painstaking care with which it has been compiled 

 and arranged, it cannot be denied that there are some portions of the re-arranged 

 classification which are open to doubt ; and, possibly, to no group of fossil fishes 

 does this apply more forcibly than to the Lamnidse. I propose, therefore, to 

 briefly review the most salient characteristics of the genera composing the 

 Lamnidae, especially those found in the chalk of Scandinavia, and di-awing such 

 deductions therefrom as appear to me most reasonable. 



The following genera are included in the family Lamnidse : — 



Sphenodus, Agass. (Orthacodus, Smith Woodw.). 



Alopecias, M. and H. 



Cetorhinus, de Blainv. (Selache, Cuv., Hassfe). 



Carcharodon, M. and H. 



Corax, Agass. 



Otodus, Agass. 



Oxyrhina, Agass. 



Lamna, Cuvier. 



Odontaspis, Agass. 



Scapanorhynchus, Smith Woodw. 



Sphenodus comprises four or five species, of which only the teeth are known, 

 characterised by a wide base, with a slender median crown. All the species are 

 found in the Jurassic rocks of the Continent, but have not been found in England. 

 The genus Alopecias is also restricted to the Continent, and is found in the 

 Molasse of Baltringen and the Eocene strata of Prussia. Selache or Cetorhinus, 



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