ZONE OP AMALTHEUS SPINATUS. Ill 



Dr. Emerson found the Spinafus-Schichten well exposed at Liithorst, near Markol- 

 dendorf, and in a soft, greyish, shaley clay he collected Amaltlieus spinatus, Brug., 

 Belemnites clavatus. Mill., Turbo paludincef or mis, ScMb. The rich Ammonite-ironstone, 

 which was formerly worked between Liithorst and Hiinnesriick, probably belonged to 

 this zone. 



A. von Strombeck' described the upper beds of the Amaltheenthone with Amal. 

 spinatus in the Helmsted Jura ; and Senator H. Romer found the same in his 

 garden near Hildesheim with Amal. spinatus, Gresslya ventricosa, Limea acuticosta, 

 and Pecten cequivalvis. Other localities described in the works of Ewald, Bornemann, 

 and Wagener, might be enumerated to show that this upper portion of the Amaltheen- 

 thone is widely distributed in North Germany. 



In Prance Professor E. Deslongchamps^ gives a good profile of the Lias a Belemnites 

 near Caen, in which we find (No. 4) the thick limestone separated by thin argilo- 

 calcareous layers with Aegoceras Bechei, Lytoceras fimhriatum, Belemnites clavatus, 

 Gryphcea cymbium, Terebratula suhovoides, Wald. punctata, Jthyn. tetraedra, Bhyn. rimosa, 

 and Spiriferina rostrata. This bed is overlain by (No. 5) a bank of sandy limestone, in 

 part finely oolitic, containing Amal. spinatus, Amal. maryaritatus, Belemnites niyer, 

 B. arcuarius, Pleurotomaria siduralis, Pecten cequioalvis, P. disciformis, Grypheea 

 cymbium, Terebratula quadrijida, T. punctata, T. Edwardsii, Bhyn. tetraedra, and 

 Spiriferina rostrata. This appears to be the equivalent of the Marlstone rock-bed of 

 English authors, as it is overlain by (No. 6) the Couche a Leptaena, which, as we shall 

 presently learn, forms the lower bed of the Upper Lias. Amaltlieus spinatus is collected 

 in other localities in Calvados ; and is found likewise at Avesnes, Doubs, at Saint- Amand 

 Cher ; at Grundershofen and Selzbrunnen, Bas Rhin ; in the Departments of Meurthe, 

 Moselle, Lozere, Haute-Saone, and Aveyron. In the Jura Department Marcou 

 separated his "■ Marnes a Plicatules," with Amal. spinatus, Belemnites Briiyuerianus, 

 Jjima Hermanni, Plicatula spinosa, Gryphaa cymbium, from the underlying beds 

 containing Amal. margaritatus, and was the first to point out the important differences 

 which exist between these two zones. 



In Luxembourg Amal. spinatus has been collected from the " Macigno d^Aubange," 

 near Athus, which is considered by Chapuis and Dewalque* as the equivalent of the 

 Marlstone and ironstone of English authors. 



Dumortier^ says that Amal. spinatus is found only in the uppermost portion of the 

 Middle Lias, in the horizon of Limea acuticosta, where it is accompanied by Avicula 



' " Die Liasmulde von Markoldendorf ;'' ' Zeitsch. d. Deutsclien geol. Gessellsch.' Jahrg., 1 870, p. 303, 

 vol. xxii. 



^ 'Geognost. Karte des Herzog. Braunschweig,' 1856. 



* 'Etudes Jurassiques Infer, de Normandie,' pp. 59 — 60, 1864. 



* ' Fossiles des Terr, second, de Luxembourg,' p. 12, 1853. 



s 'Etudes Paleont. du Bassin du Rhone,' torn, iii, p. 213, 1869. 



