A. E. Ortmann — Climatic zones in Jurassic times. 263 



mayr gives no explanation of this peculiar mixture. Regard- 

 ing, however, the local position of these beds, quoted by 

 himself, on the narrow limits between the Middle-European 

 and Mediterranean Jura, that is to say, between the deposits 

 formed in shallow water and those formed in deeper water 

 (Aptychus-beds), we must assume undeniably that in this 

 region in question the precipice of the sea bottom must have 

 been situated : a Jurassic Continental border must have been 

 present there ! Then there are only three cases possible. 

 Either the Mediterranean Cephalopod-facies is present there in 

 shallow water, as JSTeumayr seems to suppose. Or the Coral- 

 reefs grew there in deep water, which is very hard to believe. 

 Or there was present a third condition, namely, the Cephalo- 

 pod-beds of Stramberg were deposited like the other Cephalo- 

 pod-beds of the Mediterranean province in deep water, but 

 the corals and other fossils indicating shallow water did not 

 live there, but were transported thither. Such an occurrence 

 can be imagined the easier, since these beds are situated on the 

 continental border, and if the precipice of the sea bottom was 

 a steep one, Coral-fragments from the Coral-reefs living in an 

 upper level, and specimens of the other shallow-water-fauna 

 could roll down to the bottom situated in a lower level and 

 could be deposited in the Cephalopod-beds formed there. 

 That such conditions were actually present in that locality is 

 confirmed by the petrographic nature of the Stramberg-lime- 

 stone, as described by Bohm (1. c. 660). According to him this 

 limestone often may be called a breccia, and, indeed, respecting 

 one place he says : " Angular, larger or smaller fragments of a 

 light gray limestone are embedded here in a dark gray to 

 pitch black matrix. The light gray limestone is filled with 

 Corals" (" ist von Korallen fcermlich durchspickt.") * 



We need no more evidence for the supposition made here. 

 The conditions of the Stramberg-beds, quoted by Neumayr as 

 adverse to the theory of a formation of the Middle-European 

 and Mediterranean Cephalopod-deposits in different depths of 

 the sea, prove to be a support of this theory when we consider 

 the situation of these beds and their petrographic character. 



Besides there is a third topographical cause,' which may be 

 held responsible for differences of faunas deposited at the 

 same time: the different characters of the facies. E"eumayr 

 alludes to this point only incidentally, and generally he passes 

 over it without giving it due consideration. Concerning the 

 Mediterranean and Middle European provinces he says 



this fact lacks confirmation. According to Bohm (Die Bivalven der Stramberger 

 Schichten.— Palseontographica, Suppl. II. 4. 1883 p. 660-662) the different faunas 

 are really found in the same rocks. 

 * The italics are mine. 



