392 



paper with illustrations, in the Journal of the Geol. Soc. (Zeitsch. 

 d. deutschen geol. Gesellsch. Jahrg. 1863.) I possess a copy of 

 another work by him, a scarce tractate on the succession of the 

 beds of the Under and Middle Lias in North Germany, entitled 

 "Die schichtenfolge des unterem und mittleren Lias in 

 Norddeutschland von Herrn U. Schlonbach in Salzgitter, 

 Berlin, 1863." 



The Liassic sea of North Germany communicated with that 

 of Wurtemberg and Bavaria on the South, in a way still very 

 far from clear. Very likely the communication was along the 

 triassic rocks by Gottingen, Eisenach, Gotha, Cobourg, and 

 Cassel, as we may presume from certain traces of the lower 

 divisions of the Lias, which stand here and there in testimony 

 of the ancient extension of the deposits. We would press into 

 our service the account given of some of the higher divisions. 

 The Middle Lias of Markoldendorf has been well-known to 

 many geologists for its fossil fauna, through Dr. A. Romer, who 

 treats upon its palaeontology in his " Versteinerungen des 

 Norddeutschen Oolitengebirges," Hanover, 1836. The M. Lias 

 lies in a curious trough-like form of elongated oval shape, 

 running with a longitudinal axis from North West to South East 

 between Markoldendorf and Einbeck, situated on the river Em, 

 about 40 miles South of Hanover. This so called Liasmulde or 

 Lias-trough, is very instructive from the sequence of the strata 

 having been preserved through the quiet deposition of its 

 sediments. The locality has been well explored and the result 

 fully given by Dr. Emerson, in the German Geol. Journal (Band 

 XXII der Zeitsch. d. deutsch. Geol. Gesch. 1870, p. 271). The 

 trough is sharply faulted near its western boundary; but on 

 the North West lie some detached strata of the Spinatus Zone 

 at Luithorst. A short reference to these will be suggestive as 

 to the original sequence and the extent of these particular beds, 

 the exceptional circumstance being that the Spinatus Beds, no 

 doubt in consequence of an oblique compound fault or a lateral 

 branch of it, has been brought down to repose upon the Am. 

 centaurus beds which would be equivalent in position to the 

 lower portion of our Ain. Capricormis Zone; — so that all the 



