ESTHERIA MINUTA. 47 



At pp. 113 and 114, we Lave the following section of the beds in which P. minuta occurs, in 

 descending order : 



Feet. 

 Dolomitic rocks of the gypsum-group. 



Greenish-grey marl-slate 1 



Yellowish-grey, dolomitic, marly beds, with some impressions of Plants, Lingula 



tenuissima, and Posidonia minuta 2| 



Grey dolomite a 



Dolomite, with indistinct Shell-remains 1 



Aluminous sandy shale, with indistinct Plant-remains, carbonaceous patches, and 



much mica. Equivalent to the sandstone of the Lettenkohle-group 4f- 



Dolomite #. 



Dark, ash-grey, somewhat sandy shale, with calcareous and sandy nodules 1 



Grey dolomite 1 



Blackish-brown, sandy, and micaceous marl-slate, full of carbonaceous patches, 



and with remains of Fishes and Reptiles. Equivalent to the Lettenkohle 5| 



Ochre-yellow, dolomitic marl 3|. 



Ash-grey, shaly clay, with fragmentary shells 7\ 



Yellowish-grey dolomite. 



This section was taken from the shaft above the Bore-hole No. 3, near Rottenmunster, and from the 

 neighbouring bank of the Prim. 



At pp. 116 and 117, the section of the " Posidonia-marls," near Rietheim, is given thus :—" Above 

 Rietheim, near Hall, 1 there are on the Muschelkalk a few inches of dolomite, full of remains of Reptiles 

 and Fishes, then the Lettenkohlensandstein. 



" Tn the quarries between Rietheim and Bieberfeld the sandstone (Lettenkohlensandstein) is thirty to 

 thirty-five feet thick, in beds of as much as three and a half feet thick. It contains a quantity of Reptilian 

 and Fish remains, and fine impressions of Plants ; thereon lie sandy marls, passing into shaly sandstone, 

 and containing many Plant-impressions ; light-grey in colour, passing into yellowish-grey (eight to ten feet 

 thick) ; yellow and grey marl, harder downwards, and dividing itself into beds of five or six inches thick, 

 rich in Posidonice. Above that come variegated marls. Above the Posidonia-marls appear here and there 

 the Lettenkohle, then again yellow, and lastly variegated marls." 



At p. 121, he adds: — "The Mergelschiefer [marl-shale] above the Lettenkohle is of grey, yellow, or 

 green colour, and often passes into shale, sandstone, or dolomite. It contains Reptilian remains, Fish 

 remains (Acrodus or Ilybodus), and Plants {Equisetum arenaceum, 2 Bronn, Tceniopteris vittata, var. major, 

 Brongn., Pterophgllum longifolium, Brongn.), also Posidonia minuta, Lingula tenuissima? and a bivalve 

 like Sanguinolaria in form. 



1 In WUrtemberg, thirty-five miles north east of Stuttgart. 



2 This is the Equisetites Bronni, Sternberg, and the Catamites arenaceus minor, Jaeger. 



3 According to Alberti, op. cit., p. 318, Lingula tenuissima, Bronn, occurs in the Dolomite, the 

 Lettenkohlengruppe, in the Muschelkalk, and in the Bunter Sandstone. It occurs, according to Bornemann 

 ('Org. Reste Lettenkohl.,' 1850), rarely in the Myacites-clay of the Lettenkohle-group, but more abun- 

 dantly in certain of the passage-beds between that group and the Muschelkalk. Having examined 

 several specimens of Triassic rocks containing Lingidee, namely, those already mentioned (p. 44), and some 

 others kindly lent me by M. Engelhardt, of Niederbronn, and Dr. Schimper, of Stuttgart, I have noticed 



