MUSEUM OF THE NATURAL HISTORY SOCIETY. 251 



Name and Locality. Reference. 



Dorypterus Hoffmann!, Germar, Minister, Beitr. V., 

 Loc— Midderidge. PI. 14, f. 4. 



Nat. Hist. Trans., 

 Vol.4,p.243,P1.9,10. 



Fam. ccelacanthllle. 



Gcelacanthus granulatus, Ag., Poiss.Foss.IL,P1.62. 



Loc. — Midderidge. Perm. Poss., p. 235, 



PL 28*. 



REPTILIA. 



Oed. RHYNCHOCEPHALIA. 



Proterosaurus Speneri, H. v. Meyer, Geinitz, Verst. Zech- 

 Loc. — In Marl-slate at Midderidge, near stein, p. 3, PI. 1. 



Bishop Auckland. Nat. Hist. Trans., 



Vol. 4, p. 233, PI. 6. 



Proterosaurus Huxleyi, Han.etHowse, Nat. Hist. Trans., 

 Loc— In Marl-slate at Midderidge, near Vol. 4, p. 237, PI. 7. 

 Bishop Auckland. 



Remarks. — The foregoing beds — the Marl-slate and beds of 

 Magnesian-limestone — are all the rocks in these counties that 

 can be referred to the Permian Group upon palaeontological evi- 

 dence. The Yellow Sand that lies immediately under the Marl- 

 slate, when the latter is present, is a local deposit, and of very 

 variable thickness and limited area. In some sinkings for coal 

 it forms — or has formed — a most formidable hindrance to the 

 success of the undertaking, and much time and money have been 

 spent in penetrating through it. In other sinkings it has not been 

 observed, and that within no great distances from places where it 

 is known to be of great thickness and saturated with a copious 

 supply of water. It disappears entirely in the South of Durham, 

 where the Marl-slate is seen to rest on the denuded «edges of the 

 lower strata of the Coal-measures. In structure this bed is com- 

 posed of coarse gritty sand, incoherent in many places, and 

 strongly false-bedded, especially as seen in the remarkable section 



