446 Mr. H. J. Carter on the 



and contains no fossils, but in others is almost made up of a large 

 flat, thin fossil with an abruptly prominent centre closely- 

 resembling Lycophris di'sjmnsus. Its surface is covered with 

 small tubercles (but they are not, I think, united by stellate 

 lines). Tliis fossil measured 2^ inches in diameter, l-20th 

 inch thick, and 2-lOths inch in the centre." Among the 



specimens which Dr. Cook kindly sent me at the time the 

 central inflation considerably differs in thickness, since in 

 some instances it is so slight that it is hardly distinguishable. 

 But whoever studies the Foraminifera must be prepared for 

 such diff'erences, and must therefore be correspondingly careful 

 as to the value he attaches to them in specific distinction. 



It will now be seen that d'Orbigny's illustrations do not 

 entirely accord with what has been stated of the Maestricht 

 fossil, which was first described and illustrated by Faujas de 

 Saint-Fond in 1799 (' Histoire Naturelle de la Montague de 

 Saint-Pierre de Maestricht), in so far as there are no 

 " columns " represented by d'Orbigny in the " Coupe verti- 

 cale" of his Orhitoides media {I. c.) and no granulations on 

 its surface, but in lieu thereof there are sinuous lines 

 extending from the centre to the circumference and a central 

 papillary projection on each side ; while in the fossil from 

 Maestricht the papillary projection is on one side only, as 

 represented by Faujas de Saint-Fond in his fig. 3, as I 

 learn from the tracing kindly made for me by Mr. Jones, of 

 the Geological Society. Still, in other respects d'Orbigny's 

 illustrations would suffice for the Orbitolitean type of the 

 Maestricht fossil to which I have alluded. 



What fossil, then, do d'Orbigny's illustrations in totality 

 represent ? Let us take his other reference, viz. that to 

 Orhitolites media, d'Archiac, from the Chalk in the south- 

 west of France, of which, as I have no specimen and there is 

 no illustration to his description, the best thing that I can do 

 is to append his own words in the following extract : — 



" Orhitolites media, nob. 



" Lenticulaire, deprim^. Du centre de chaque face partent 

 de petits sillons nombreux, qui se croisent en se dirigeant 

 vers la circonfdrence ; pores irreguliers c\ la surface ; souvent 



