264 University Geological Survey of Kansas. 



and ferocity. Below is the synopsis of the family Saurodontidse , 

 as given by Cope : 



I. Jaws without foramina on the inner face below the alveolar margin: 



a. Teeth cylindric: 



Teeth of unequal lengths ; some of them greatly de- 

 veloped Portheus. 



Teeth of equal length Ichthyodectcs. 



ao. Teeth compressed, knife- like: 



Teeth of unequal length; some of the anterior 



greatly developed Erisiethe. 



Teeth equal Doptinus. 



II. Dentary bones pierced by foramina below the alveolar border: 



Teeth with subcylindric crowns Saurodon. 



Teeth with short, compressed crowns Saurocephalus. 



Professor Cope also says : " There are some other forms to be 

 referred to this family, whose characters are not yet fully de- 

 termined. Thus Hypsodon Agass., from the European chalk, is 

 related to the two genera first above named, but, as left by its 

 author in the ' Poissons Fossiles,' includes apparently two 

 generic forms. The first figured and described has the man- 

 dibular teeth of equal length. In the second, they are unequal, 

 as in Portheus, to which genus this specimen ought, perhaps, 

 to be referred. Retaining the name Hypsodon for the genus 

 with equal mandibular teeth, its relations to Ichthyodectes re- 

 main to be determined by further study of H. lewesiensis. The 

 view of the superior walls of the cranium given by Professor 

 Agassiz presents characters quite distinct from what I have ob- 

 served in Portheus. " Hypsodon has since been shown to be a 

 synonym of Pachyrhizodus , Portheus a synonym' of Xiphactinus, 

 Erisiethe a synonym of Protosphyrxna, and Daptinus a synonym 

 of Saurodon. Thus, it is seen that the old synopsis will no longer 

 hold, so I give the following revised one : 



a. Teeth large and of unequal length Xiphactinus. 



b. Teeth medium, of equal length . Ichthyodectes. 



c. Teeth small and fringe-like Oillicus. 



The two large oval scales from the chalk of Lewes, figured by 

 Agassiz 22 as Cladocyclus, bear a close resemblance to those of 



22. Poiss. Foss., vol. V, pi. XXV«, figs. 5, 6. 



