50 FOSSIL ESTHERI^. 



part 3, p. GO, after a list of synonyms, of which Ave have availed ourselves (with some 

 slight corrections), Posidonom^a minuta is stated to occur in the following localities. 



Rarely in the Bunter Sandstone, with plants, at Snlzbad and Corcelles ; also 

 In the uppermost part of the Muschelkalk (20, near Biberfeld in Whrtemberg ; more 

 plentiful in the Lettenkohlen-Gruppe (k) of Wilrtemberg on the Schwarzwaltl, near 

 Rottweil, at Rottenmlinster, and elsewhere (o, p, Alberti, r Quenstedt) ; also at 

 Pforzheim and at Sinsheim, near Heidelberg ; in the uppermost layers of the 

 Keuper Sandstone (ss) in Wilrtemberg (Tiibingen) ; and, as it appears, still higher, 

 increasing in size (to T" long). Lastly, at Ilassfurth, near Schweinfurth (Goldfass), and 

 in the Keuper, near Weimar ; in the Upper Keuper, at Ellichausen, near Gottingen, and 

 in the Upper Bunter Sandstone, near Dassel, in the Sohing. Posidonia Keuperina has 

 been recorded from the Lower Keuper beds at Hall, in Swabia, and is probably identical. 



On the other hand, adds Bronn, the occurrence of the true P. minuta in the Russian 



Copper-sandstone (Kutorga, in Jahrb., 1844, p. 742, and his Zweit. Beitrag zur Paliiontol. 



Russl., 1844, p. 14, pi. 1, fig. 4 (Comp. Jahrb., 1849, p. 754), and in the Keuper of the 



'Venetian Alps (Catullo in ' N. Ann. Scienz. di Bologna,' 1846, Eebbr.), is very doubtful. 



Thurhigia. — The published notes on the occurrence of Estheria minuta in the Thu- 

 ringian Trias are as foUow : 



1849. lierbst ('Neues Jahrbuch, f. Min.,' 1849, p. 545) refers to P. minuta being 

 met Avith in the Keuper of Weimar. 



1856. Dr. J. G. Bornemann has treated of Posidonia minuta in his work 

 'Ueber organische Reste der Lettenkohlengruppe Thiiringens,' 4to, Leipsic, 1856, p. 179, 

 and figures it (indifferently) in his plate 1, fig. 9. It occurs, he says, at Johaunisthal, 

 near Miihlhausen, and elsewhere, in great numbers on the surface-planes of the Myacites- 

 clays of the Letten-coal group, associated with Tric/onia transversa} Bornem., and 

 Myacites letticus, Bornem., and in a similar state of preservation ; and also in the black- 

 grey shales Avhich accompany the Lettenkohle, but in bad preservation. It reaches 

 o-enerally to about three millemetres in length. Venus donacina, Goldf., and Linpda 

 detmissima, Bronn, with remains of Acrodus Gaillardoti, Ag., and teeth of Placodus also 

 .occur in the Myacites-clays. 



1857. In a paper on the Entomostraca of the Trias of Tlmringia, in the ' Zeitschrift 

 deutsch. geol. Gesellschaft,' vol. ix, p. 198 (1857), K. von Seebach mentions the occurrence 

 of Posidonomya minuta^ Bronn, in marls, immediately underlying the Lettenkohle of the 

 Keuper, at the Gelmerodaer Berg and elsewhere, near Weimar, Avhere it is accompanied 



.with Acrodus Gaillardoti, Ag., Colohodus varius, Gieb., Plant-remains, Myoplioria 

 'transversa, Myacites, Cythere^ Pyrus, Seeb., C. procera, Seeb., C. teres, Seeb., and C. 

 dispar, Seeb. 



1 This is the Lyriodon vulgare, Goldfuss, 'Petref. Germ.,' ii, p. 198, pi. 135, fig. 16, c. 

 - Von Seebach terms the first three of these Entomostraca Bairdice, but to me they do not appear to 

 belong to that subgenus. 



