14 GEOLOGICAL MEMOIRS. 



Miesbach, and of the neighbourhood of Traunstein, which Emmrich 

 forwarded to me, I found — 



Lamna contortidens, Ag. Ostraea longirostris, Lam. 



Panopaea Hebertiana, Bosq. -ventilabrum, Goldf. 



Ostrsea cyathula, Lam. Pleurotoma laticlavium, Beyr. 



all of them true lower Miocene forms, amongst which Ostrcea cyathula^ 

 as a widely extended typical shell, is of great importance ; the other 

 fossils, with the exception of the Echinus described by Schafhautl, 

 were too ill preserved to allow me to pronounce positively respecting 

 them. The Cyrena-marls which overlie this formation produced on 

 the other hand — 



Cyrena subarata, Br., forming Cerithium plicatum, Lam., especially 

 whole beds. var. Galeotti, Nyst. 



Tichogonia Brardi, Desk., partly Melanopsis praerosa, Lam. 



with remains of colour. Planorbis ? declivis, A. Braun. 



Cerithium margaritaceum, Lam. Cytheridea Mullcri, Miinst. sp. 



A plant not to be distinguished from Cupressites freneloides, 

 Ettingsh., was found in the clay of the Grossthal beds ; the pitch- 

 coal of the Peisenberg and of the Leiznachthal beds contained remains 

 of flattened Planorbes, and Helices, one large species of which was 

 ribbed, entirely corresponding with H. Ramondi, and a XJnio which 

 could not be accurately made out. My above-mentioned statement 

 appears therefore to be sufficiently confirmed. 



The position of the Septaria-clay and of the Cyrena-marl has 

 occasioned a discussion between Prof. Beyrich and myself. I now 

 believe, according to the recent discoveries near Cassel (Hesse), that 

 the Septaria-clay there overlies the representatives of the Cyrena- 

 marl or the lower brown-coal formation, the fossils of which have 

 been described byDunker*. It is thus admitted that it is somewhat 

 younger, but certainly not much, as fossils of the Septaria-clay occur 

 partly in the marine sands of Alzey, and partly in the Cyrena-marl. 

 It would thus, as the deposit of a true saline northern ocean, belong 

 to about the same age as the brackish Cerithiuin-limestone of the 

 Mayence basin, but by no means younger than the upper deposits of 

 this basin, as Beyrich supposed, probably because he referred all the 

 brown-coals of Cassel to the same age. It has, however, now been 

 shown that the occurrence of the not very uncommon Leda Beshayes- 

 ana with shells of the Cyrena-marl near Selgen, in Rhine Hesse, which 

 were supposed by my late friend Voltz to be in a primary position, 

 are in a secondary one, i. e. that the bed containing the fossils is a 

 pebbly diluvial loam. Now as Leda Beshayesana has been found 

 near Mosbach, not far from Wiesbaden, in the diluvium accompanied 

 by tertiary fossils from very different beds, my former opinion of its 

 occurrence in situ in the Mayence basin in its original or primary 

 deposit must be modified. It rather appears to have been washed 

 into the basin during the diluvial period from deposits of Septaria- 

 clay situated further north, and to have become mixed up with 

 the fossils washed out of the upper- beds of the underlying tertiary 

 formation. Nevertheless, however, many other fossils undoubtedly 



* Programme of the Upper Trade Schools at Cassel, 1853, p. 4. 



