ESTHERIA MINUTA. 



49 



Keuper 



! Yellow, hard sandstone, with Bone-bed. Modiola minuta, Avicula gracilis, 

 and Myacites. Patches of coal. 

 Red clays. 

 d /White sandstone, alternated with bright-coloured and blue clays ; coal- 

 patches ; silex and agate. Reptilian bones. 



c Variegated marl and sandstone, with foot-tracks and ripple-marks. Shells 



rare. 



b Green and reddish sandstone. Plants. 



a Gypsum and marls. Shells. Reptiles. Ceratodus. 



Dolomitic limestones. Estheria minuta, Lingula tenuissima, Trigonia 

 Goldfussii, Gervillia socialis. Fishes. 



(d. Lettenkohle 



c. Muschelkalk 

 proper 



Muschelkalk... ( 



b. Salt-group 



Marl and clay. Mastodontosaurus. 



Grey sandstone, with Equisetites 



Grey sandstone, with Bone-bed. Coprolites, Gryolepis tenui-striatus, 



Acrodus Gaillardoti, Psammodus, Hybodus plicatilis, Dracosaurus 



Bronnii. 

 Dolomite, and limestone. Pemphyx Sueurii, Fucks Ilehlii. 

 Thin marly limestones. Saurian and Fish-remains, keratites nodosns, 



Encrinites liliiformis, and abundance of marine shells. 

 Limestones. 



(Limestone. 

 Clays with gypsum and rock-salt. 

 Limestone. 



Banter 



a. Wellenkalk 



J b. Red sandstones 

 [a. Sandstone. 



f Wellenkalk 

 I Wellendolomit 



Marine shells, &c. 



Quenstedt thus refers to Estheria minuta and Lingida tenuissima of the Keuper, in his 'Flozgebirge 

 Wiirtembergs,' pp. 71 and 75. "Above the Lettenkohle (he says) is an extremely hard dolomite, 

 several feet thick, lying between thin dolomitic beds, darkish [in colour, and streaked with yellow. 

 Careful search in the thin dolomites overlying the hard variegated dolomite, may be made with 

 interest, for at every splitting of the beds the little Posidonia minuta scales off in thousands ; and in some 

 specimens a thin-shelled Lingula occurs, which in this association, although without any very striking 

 characteristic of its own, becomes the strongest boundary-mark for the Muschelkalk formation. This fine- 

 striped Lingula, called tenuissima, on account of the thinness of its shell, is distinguished only by its place 

 of occurrence from the Lingula of other formations. It lies always above the sandstone and variegated 

 dolomite (Flammendolomit), and scattered among the Posidoniee. P. minuta is seldom many lines in 

 diameter, it has an obliquely oval shell with a straight hinge, and is only on account of its concentric 

 wrinkles recognised as a Posidonia. The specimens might be taken for badly preserved Astartes, or many 

 other shells ; so little is known of its generic characters." 



Again, in his 'Handbuch der Petrefaktenkunde,' Tubingen, 1852, p. 51G, Quenstedt says — '' Posido- 

 nomya minuta (pi. 42, fig. 13 ; 'Zieten. Verst.,' pi. 54, fig. 5) lies in millions in the dolomitic beds above 

 the Lettenkohle. This little longish shell may as well belong to an Astarte, or any other bivalve. From 

 the impressions this cannot be decided." 



1851. From H. G. Bronn's third edition of his 'Lethaea Geognostica/ 1851, vol. ii, 



