﻿DEBEY ON THE AIX-LA-CH APELLE DISTRICT. 



Ill 



dopsis*, and indeed it is probable that ultimately some of the above 

 will prove to be identical with the last-named genus. 



Of the Dicotyledonous leaves it is worthy of remark that the Phyl- 

 lites Geinitzianus and Ph. emarginatus, from the "Quader" of Si- 

 lesia, lately described by Prof. Goeppert in the Acta Leop. vol. xxii. 

 pt. 1. p, 361. figs. 5, 6, 7, 10 and 11, exhibit an agreement with Dr. 

 Debey's genus Bowerbankiaf; whilst, on the other hand, of the 

 CredneritE (which especially appear to belong to the "Upper Quader" 

 of Blakenburg, occur only as a few species in the Silesian "Quader" 

 and in the Niederschona beds, and are altogether wanting in the 

 Bohemia "Quader") there is not a trace in the Aix-la-Chapelle 

 Sand. 



A stratigraphical arrangement of the best-determined vegetable 

 remains of the whole Chalk-formation exhibits the greater prevalence 

 of plants in the lower Cretaceous rocks of Germany. The proportion 

 is approximately as follows X ' — 





Upper Chalk. 



Middle Chalk. 



Lower Chalk. 





White Chalk. 



Greensand. 



Lower Quader. 





Upper Quader? 



Gault. 



Aix-la-Chapelle 









Sand. 





12 







15 





6 







28 













2 









3 



5 





1 



1 



5 





1 







1 





4 



4 



20 









3 



5 





5 







3 



Leaves (Dicotyledonous), unde- 











4 



1 



26 













8 











The remainder of the memoir is occupied by nmch interesting 

 matter relating to the Chalk-formation, — especially, a review of the 

 faunas of the Cretaceous deposits of different countries, and general 

 considerations on the Cretaceous Period, — and by a description of the 

 Tertiary and Post-tertiary deposits of the neighbourhood of Aix-la- 

 Chapelle. [T. R. J.] 



* For description of this genus and of six species from the Iron-sand of Aix-la- 

 Chapelle, see Dr. Dehey's paper, Ueber eine neue Gattung urweltlicher Coniferen 

 aus dem Eisensand der Aachener Kreide. Verhandl. nat. Vereins preuss. Rheinl. 

 Bonn, 1847, p. 126 et seq. 



f Some of leaves are from 4 to 6 inches in length, and occur in a beautiful state 

 of preservation. [Dr. D. in Mt.~\ 



% This Table is corrected from that published by Dr. Debey, together with a list of 

 Cretaceous plants with references, synonyms, &c, in his Paper, Uebersicht der 

 urweltlichen Pflanzen des Kreidegebirges uberhaupt und der Aachener Kreide- 

 schichten insbesondere. Verb.. Ver. pr. Rheinl. 1847, p. 113 et seq. 



