236 CATALOGUE OF THE LOCAL FOSSILS IN THE 



earthy, and in some localities regularly bedded and oolitic. 

 The upper beds, in some localities, are oftentimes strongly un- 

 dulated and much broken up, and the fissures filled with masses 

 of breccia derived from strata or beds belonging to the Upper 

 series. The only trace of fossil that I have seen from the 

 Concretionary portion of this series was obtained from some 

 laminated marly beds which were enclosed and isolated in the 

 extensive and thick stratum of Concretionary rock which was 

 worked or quarried extensively at the Trou Bocks, near South 

 Shields, for the pier works at the mouth of the Tyne. This 

 fossil was a fragment of Caulerpites selaginoides, a coniferous 

 plant, which occurs in the Marl-slate and in the Limestone of 

 the Upper series in England, and in the Keupferscheifer of Ger- 

 many. 



Locality. — It occurs in the outlier on the top of the cliff at 

 Tynemouth, also in Whitley Quarry and Cullercoats Bay, North- 

 umberland, where the Magnesian-limestone and the Marl-slate 

 are brought in by the "Ninety-fathom Dyke," or fault. It 

 occupies in great thickness the top of the cliff from the Trou 

 Eocks, at North Point, two miles south of the mouth of the 

 Tyne (where it rests for half a mile on the disturbed and denuded 

 surface of the Lower compact limestone) to the North end of 

 Marsden Bay, where its upper surface is broken up, fissured, 

 and filled in with breccia derived from the lower beds of the 

 Upper series, under which, in a disturbed, confused, and broken 

 up state, it disappears. 



Shell-Limestone. 

 German equivalents : — Zechstein-dolomit. 

 The Shell-limestone is upon the same horizon, and forms the 

 westernmost or basseting portion of the preceding deposit. It 

 is an irregular amorphous mass, without any signs of stratifica- 

 tion, of highly crystalline limestone, in some parts exceedingly 

 hard and fine-grained, and in others friable, earthy, and rubbly, 

 and consisting of broken pieces of polyzose and shells. It con- 

 tains an assemblage of the most characteristic fossils of the 

 system. "When seen in section, it rests on the upper, often 



