38 
This description is, on the wiiole, as satisfactory as any that 
conld he founded on single teeth. But it does not apply to 
some teeth which Agassiz evidently considered to belong to this 
genus. This difficulty caused Sanvage to separate certain teeth 
from Strophodiis, and on these he founded his genus Curtochcs. 
In a paper printed in the proceedings of the “ Societe 
academique de Boulogne-sur-mer,” for 1866, and afterwards 
re-issued in his “ Poissons fossiles des formations secondaires 
du Boullonais,” he gives the following description of 
Curtochcs :—“ Dents ovales on arrondies, reticulees en dos 
d’ane. Nons avons cree ce genre pour les dents qui different 
de celles de Strophoclus, en ce qu’ elles ne sont pas inflechies 
suivant leur longuer, mais hombees.” 
Of this division, too, we may fairly say that it is as sound as 
any classincation founded on detached teeth can be. But the 
discovery of an almost perfect series of teeth in the Grreat 
Oolite of Caen at once gave unity to our knowledge hj ex¬ 
hibiting the dentition of the genus. This important and 
interesting specimen wns described and figured by Professor 
Owen* as Strophodiis medius. Any remarks in this paper 
involving a reference to the dentition of Strojohodus will be 
founded upon the description quoted above. A glance at the 
specimen referred to reveals the great diversity that obtains 
between teeth in the same jaw. Sauvage’s genus Curtodus is 
evidently founded on teeth of the extreme lateral rows. It must 
be observed, though, in justice to this able palaeontologist, that 
this specimen of S. medius was not discovered till nine years 
after Curtodus had been described, so that although his genus 
cannot stand, its separation was quite warranted by the 
information then in possession of ichthyologists. 
The tooth from our owm Cornbrash (given in natural size 
PL I., figs. I and 2, and enlarged, figs. la. and 2a.) is un¬ 
doubtedly Agassiz’ Strophodiis favosiis. But unfortunately the 
S. favostis of Agassiz is a name, and nothing more. Agassiz 
gives the name in his list of species, but he neither describes 
nor figures it. This is the more unfortunate that the series 
* Geol. Mag., vol. VI., p. 193 and pi. VII. 
