ESTHERIA MINUTA. 57 



occm-, they are never found in tliera. Such pseudomorphic salt-crystals occur near 

 Liineberg, in the shales with Linc/nJa tenuissima, alternating with the limestones, just 

 above the Lettenkohle group ; in the dolomitic beds of which latter Estheria minida 

 occurs (sparingly) with Myophoria, &c. (See page 51.) So again, in England, the" 

 pseudomorphic salt-crystals occur in the Upper Keuper shales immediately overlying the 

 grey sandstones and shales containing JEstheria, but not in the Estherian shales themselves. 



Estheria minuta of the Enc/lish Trias. 



In the New Red Sandstone of England Estheria minuta is abundant at places, and 

 often occurs as well-grown individuals (larger than any from the Continent that I have yet 

 had an opportunity of seeing), and occasionally (as at Pendock) most perfectly preserved. 

 Judging from the materials at my command, I may say, that the English specimens are 

 more variable in their shape than those found in Germany, since they are apt to contract 

 the posterior portion of the carapace-valves, and so take a subovate form ; but I cannot 

 say that such a variation of outline may not be found in the foreign specimens, of which 

 I have not seen a very large series. 



The beautifully perfect condition of the carapace in PL II, fig. 1, is strongly con- 

 trasted, in its neatly definite concentric ridges, and the smooth broad intervals, delicately 

 reticulated by large fine-walled meshes, with the obscurely wrinkled stony casts, indicated 

 by figs. 4 and 5, and with the coarse-walled meshes into Avhich the original reticulation 

 is here modified, the animals having been fossilized in a less accommodating matrix. The 

 German specimens (PI. I, figs. 28 — 30) have suffered similar deteriorations. 



The measurements of some of the best English specimens are as follow : 



r Height, rather more tliau ^|- inch") 



FromPendock Length of valve % „ Proportion, 2 to 3 by 1, or 



Thickness of closed valves, j Itoljbya. 



^ less than -jig- „ -' 



(Heio'ht . "^ -T- j> 1 



From Shrewley Common and] ° *i_ 2. " i Proportion G to 9 by 4, or 1 to 



Pendock ] '"^ * ^'^ " f -libyf. 



Thickness rather less than ^ 



fHeight, rather less than t> inch"! 

 From&omerton J^ ^^^ f^ jProportion 23 to30, or 1 : l|-f 



In my examination of English specimens of Estheria minuta, I have had before me 

 specimens from the Upper Trias, or Keuper, of Somersetshire, Worcestershire, Warwick- 

 shire, and Leicestershire. 



]. A specimen of pinkish-white, fine-grained sandstone, from Shrewley Common, 

 Warwickshire, with convex casts of Estherice, retaining traces of the shell and its orna- 

 ment (PI. II, figs. 5 — 7), collected by the late Mr. H. E. Strickland, and presented by 



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