116 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



shire. It appears, however, that Mr. Bean described and figured 

 Unio distortus and Cypris concentrica, from the sandstone and shale 

 of Gristhorpe Bay, in 1836*; and that Mr. Williamson, soon after- 

 wards, discovered a second species of Unio in the same bedsf. These 

 strata have been known for some time to possess two plants (Zamia 

 pectinata, Ad. Brong., and Thuytes expansus, Sternb.) in common 

 with the Stonesfield slate J; and the Megalosaurus of the latter and 

 of the Wealden of the S.E. of England were, long ago, ascertained 

 by Cuvier to belong to the same species. An indirect connection is 

 thus established between the Jurassic coal series of Yorkshire and 

 the Wealden beds above the Portland stone, and I doubt not that 

 on closer examination they will prove, by the discovery of identical 

 fossils, to be much more nearly related. 



The few geologists who still look upon the Wealden above the 

 Portland stone as a member of the Cretaceous series, will doubtless 

 hesitate before adopting the classification above proposed ; but when 

 it is recollected that the Maidstone Iguanodon and the Lonchopteris 

 Mantelli^ (Brong.) are the only fossils yet recognized as common to 

 the two systems, while the fourteen enumerated below are found be- 

 tween the Purbeck beds and Trias, as well as in the division of the 

 Wealden alluded to, their objections will probably give way. 



Megalosaurus Bucklandi, Cuv. Stonesfield slate, &c. ; Tilgate beds, &c. 



Poikilopleuron Bucklaudi, Deslongch. Caen limestone ; Tilgate beds. 



Lepidotus minor, Ag. Stonesfield slate, Portland stone ; Purbeck beds. 



Microdon radiatus, Jg. Stonesfield slate ; Purbeck beds. 



Pycnodus Mantelli, Ag. Oolite, Katisbon ; Tilgate beds. 



Asteracanthus semisulcatus, Ag, Stonesfield slate ; Purbeck beds. 



Hybodus marginalis, Ag, Lias, Stonesfield slate ; Purbeck beds. 



apicalis, Ag. Lias, Stonesfield slate ; Purbeck beds. 



,_ dorsalis, ^^. Stonesfield slate ; Tilgate beds. 



I^r — strictus, Ag. Portland stone ; Purbeck beds. 



j^ grossiconus, Ag. Stonesfield slate ; Caen limestone ; Tilgate beds. 



^^•" Ostrea distorta. Sow. Portland stone ; Purbeck beds. 

 E Cyclas angulata. Sow. Brora beds ; Wealden passim. 



- Cypris granulosa, /Sow. Brora coal-fields ; S. of England ||. 



The Stonesfield slate, Caen limestone, lithographic limestones of 

 Bavaria, and other beds of the same character, must be excluded 

 from the category of the Wealden ; for although they all contain cer- 

 tain fossils identical with those of the latter class, it is evident, from 

 the preponderance of their marine remains, that they were deposited 

 in a saline medium. The following remarks will explain the relation 

 in which I conceive these strata to stand to the estuary portion of 

 =the Wealden beds and to the marine members of the Jurassic system. 



- If a continuous section of the various deposits, formed con- 

 -'temporaneously in an estuary and in the adjoining sea, could be 



* Loudon's Mag. Nat. Hist. vol. ix. p. 376. 



t Trans. Geol. Soc. 2nd Series, vol. v. p. 236. -'^ ^ff;t moi^ * 



% Phillips, * Yorkshire Coast,' and Morris, * Catalogue of British Fossils/ !■.>•« 

 § Quart. Geol. Journ. vol. ii. p. 55. y*^ 



il The authorities for this list are. Prof. Owen in Report of Brit. Assoc, for 



1841 ; Prof. Agassiz in Brit. Assoc. Report for 1843 and in Poissons Fossiles; and 



Dr. Fitton in Trans. Geol. Soc. 2nd Series, vol. iv. 



