OPPEL AND SUESS — KOSSEN BEDS. » 



Neuhausen on the Fildern, and on the Birkengehnen near Esslingen. 

 Sometimes isolated teeth and bones are associated with the shells, 

 e. g. at Nellingen, 2\ English miles south of Esslingen. In the 

 second, the shell-bed lies 7 to 8 feet below the Bone-bed, especially- 

 near Niirtingen. The Table at p. 4 gives a synoptical view of all the 

 molluscous remains hitherto found in these deposits. 



Besides the species quoted in this Table, Prof. Quenstedt notices 

 some others, which we think are still very imperfectly known : 

 among them are Venericardia prcBCursor, Quenst. (perhaps identical 

 with Cardium Austriacum, Hauer, if we may judge from some casts 

 before us), Plagiostoma prcBcursor, Quenst., and a Lima, only known 

 at present by internal casts, — at least we are not acquainted with 

 the form of its external surface. We have not yet found in the 

 deposits in question the My a mactroides, Schloth., quoted by Albert! 

 (Monogr. der Trias-Format, p. 153), nor the Monotis incequivalvisy 

 Bronn. Pecten Valoniensis and Cardium RhcBticum have not yet 

 been found below the Bone-bed, so that Avicula contorta is the only 

 form yet ascertained to be common to this lower deposit and to the 

 Kossen beds. 



M. Alberti was the first (1834*) in Wirttemberg who noticed 

 these beds with regard to their fossil remains, describing them under 

 the name of ''Tabingen Fossiliferous Sandstonef." This distin- 

 guished geologist expressly mentions {loc. cit. p. 152) the simul- 

 taneous occurrence of teeth, bones, and shells in a fine-grained sand- 

 stone on the superior limit of the Keuper. The other localities have 

 been brought to light by the successful investigations of M. Deffner, 

 the owner of a manufactory at Esslingen. 



These shelly deposits have not yet been found in every locality 

 of Suabia where the boundaries of the Keuper and the Lias have 

 been laid open. The sandstones are either so hard that nothing 

 except carbonized vegetable remains can be got out of them, or 

 they are reduced to siliceous bands, not above an inch in thick- 

 ness, overlying the marls of the Keuper, and including the Bone-bed. 

 The Li^.s appears immediately above them ; and below them is a thin 

 layer of grey clay imbedded in the red marls of the Keuper. 



Similar circumstances are observable in many localities in France 

 and England, where the beds intercalated between the Lias and the 

 Keuper are laid open ; in some of them shell-banks (generally com- 

 posed of Pectens) seem to make their appearance J. This similitude 

 is still more striking in the Irish deposits, described by Col. Port- 

 lock §, containing Pecten Valoniensis, Avicula contorta^ and a Car- 



* " Beitrag zu einer Monographic des Bunten-Sandsteins, Muschelkalks und 

 Keupers." Stuttgart, 1834. 



t The same beds, with the same shells, occur at Tabingen, between RottweU 

 and Balingen. 



X See Strickland (Proc. Geol. Soc. vol. iii. pp. 585 & 732; and vol. iv. p. 17); 

 and Murchison (Geol. of Cheltenham, 1845, p. 54). 



§ Geol. Report on Londonderry, &c., p. 90. "VVe have previously had occasion 

 to notice this concordance (Oppel, "die Juraformation, &c." pp. 16-24). Prof. 

 Quenstedt (" Der Jura," pp. 25-31) has recently put forth the same opinion, with- 

 out, however, duly attending to the very essential difference between " Lower St. 



