06 FOSSIL ESTHERLE. 



Kcuper. Still Esllteria have not been found (to my knowledge) in these salt-bearing beds. 

 They appear to keep a definite line above the horizon of the rock-salt and beneath that of 

 the salt-pseudomorphs, and may represent a nearly, if not quite, freshwater condition 

 of the waters of the Upper Triassic period for the localities in which they occur. 



In Gloucestershire (near Tewkesbury), and near Pen dock, and at the eastern end of 

 the Malvern Tunnel, in Worcestershire (Prof. Morris), the salt-crystals 1 abound in the 

 thin sandstone imbedded in greenish-grey shale above the sandstone and shale with 

 EsthericB and plants. 



In Leicestershire Mr. James Plant has found the Keuper to be rich in these pseudo- 

 morphs at some places ; he informs me that he has taken these salt-casts most abund- 

 antly at four localities, twenty miles apart, namely, Chilwell, Orton, Beaumanor Park, 

 and Spinney Hills, near Leicester. In all these cases he considers the beds to be either 

 the Upper Keuper Marls or the sandy shales immediately beneath, except at Orton, 2 

 where, perhaps, there are the still lower sandy shales (containing Estlierice, near Leicester), 

 lying on red marl. 



Estheria minuta, Var. Brodieana. PI. II, figs. 8 — 15. 



Cyclas-ltke Bivalve, Brodie. Proceed. Geol. Soc, 1842, vol. v, pp. 14 and 15 ; Hist. 



Fossil Insects, Second. Rocks, England, 1845, pp. 58, 79, &c. 

 Cyclas, sp., Buff. Geology of Moray, p. 1842, p. 19. 



Estheria minuta, Wright. Quart. Journ. Geol. Soc, 1860, vol. xvi, pp. 3/8, 387, 395. 

 Estheria, C. Moore. Quart. Journ. Geol. Soc, 1860, vol. xvi, p. 446; and 1861, vol. 

 xvii, p. 497, 512. 



_. , f Height -iVinchl„ 



From Westbury •! , TJ ^Proportion, 1 : If. 



1 LLength f| „ J l 



/Height, rather more than -^ „ ~\ n . , r . .. . 



i T ° V f " 9 to 16, or 1 : If + 



LLength r ^ „ J 



(Height of valve T \ ,, ) , 



nn iTr • , i , 1 >> 1 2 to 1 / , UV O J 01' 



from Wamlode < Length, less than -fit » ( l 





Thickness, less than 



1 : U_, by 4— 



/Height, less than A „ j ^ fl t<j ^ or { . 



LLength, more than ^ ,, J 



From Linksfield /Height f, „ j ^ 8 to 1 1, or 1 : 1 J— 



LLength, less than -^ ,, J 



1 For notices by Mr. Strickland and Mr. Ormerod of the pseudomorphic salt-crystals, or rather 

 sandstone casts of the hollows left by salt-crystals, see 'Quart. Journ. Geol. Soc,' vol. ix, pp. 5, 187. 



2 At Orton, Mr. Plant informs me, the sandstone is only four feet thick, but is so widely spread and 

 so horizontal that it is used in its natural position as threshing-floors in barns, and on these cnn be dis- 

 cerned the pseudomorphs and ripple-marks. Such sandstone is similarly used in Worcestershire. 



