26 



FOSSIL ESTHERLE. 



ESTHERIA STRIATA, Vai'. TaTEANA. PI. I, figS. 15 — 18. 



Inch. 



Height of valve, £ 



Length 



^ Proportion 2 to 3, or 1 : \\ 



Height 

 Length 



Inch 



*? ^Proportion 5 to 7, or 1 : 1J- 



Height, nearly ^ inch") ,,*,,, , , , 



° , ^Proportion 11 to 14, or 1 :1 +. 



Length, more than ^ ,, j 



striata, from, Lammer- 

 ton, Berwickshire. 



Carapace-valves nearly oblong, but higher at the posterior third than anteriorly, boldly 

 rounded behind with a semicircular outline, obliquely rounded in front. Pig. 18 repre- 

 sents a shorter carapace than fig. 1 5 ; and some appear to have 

 FlG - 2 - been even shorter, and of a more rounded form, than this. We 



Sketch of a subquadrate } mve a corresponding occurrence of oblong or subovate, in company 

 5theria with subquadrate, forms of Estherian carapace in the case of 

 the Rhsetic E. Mangaliensis of India (PI. II, figs. 16 and 20), 

 and the Wealden E. ellipiica (PL IV, figs. 1 and 3). The out- 

 lines of the specimens figured may have been slightly altered 

 by pressure, but they are far more perfect than the majority of 

 those I have seen from Lammerton. 



The specimens of Estheria striata, var. Tateana, were kindly 

 submitted to me by their discoverer, Mr. George Tate, P.G.S., of 

 Alnwick, some years since. They are numerous, but obscure, 

 impressions or as thin rusty films, or as a faint reticulate 

 tissue, in a black and somewhat bituminous shale. They seem to have been originally 

 densely crowded ; and are associated with Fish-remains, Spirorbis earbonarim, and 

 impressions of Plant-stems. The shale belongs to the Mountain-limestone series, and 

 comes from Lammerton, in Berwickshire. 



To render the geological position of these Estheria quite plain, Mr. Tate has obliged 

 me with a succinct account of the strata and fossils observed by him in the section where 

 these shales are met with. He says — 



" The dark carbonaceous shale containing Estheria is exposed in the cliff along the 

 Berwickshire coast for upwards of a mile ; it is accessible, however, only at a few points ; 

 and Estheria has apparently but a limited distribution in the bed. I have found it 

 only near Lammerton. The section here, is as follows (in descending order) : — 



(Magnified 6 diameters.) 



either 



as 



Feet. Indies. 



1. Reddish sandstone 90 



2. Dark carbonaceous shale, with Est her ice ; where thickest, it is generally hard and 



flaggy 12 



3. Limestone, fossiliferous ; usually of a dun colour, and weathering buff 4 



