1855.] HAMILTON — TERTIARIES OF HESSE CASSEL. 135 



causes of the burning may have been, there can be no doubt that the 

 sweUmg out of the whole mass has been caused by the expansion of 

 the clay on being converted into jasper. Moreover it contains nu- 

 merous cavities, fissures, and cracks, and is split up in every direction, 

 so as to occupy more space than before the change took place. 



Another locality which we visited in the vicinity of Hesse Cassel, 

 and where marine tertiary shells also occur, is a small hollow between 

 Cassel and Miinden, near the village of Landwehrhagen. Numerous 

 clay-pits were formerly opened here, and fossils were abundant ; but 

 we only found a few broken fragments in the thrown out heaps. 

 These were chiefly bivalves ; we recognized three or four species, viz. 

 a Cardiiim, Cyprlna, Cytherea, and perhaps Pectunculus, enough to 

 show the marine nature of the water in which the clay was deposited. 

 This was overlaid by yellow marls, gradually passing upwards into 

 fine yellow sand, but as far as we could see, quite unfossiliferous. 

 This is exactly the same as occurs in the vicinity of Cassel, where 

 the shelly marls and clays are overlaid by sandy Ijeds. The same 

 formation also occurs in the section near Kaufnngen, where the clays 

 with marine shells are overlaid by yellow sands ; in the latter case, 

 however, the sands are fossiliferous. 



II. Tertiary Beds of Westeregeln near Magdeburg. 



I have already alluded to and explained the error I was led into 

 in a former communication respecting these deposits. I had in- 

 tended visiting the locality during the past autumn, but was de- 

 terred from doing so, in consequence of having received information 

 that the beds in question were no longer open or visible. I shall 

 therefore only briefly state what I have learnt respecting their posi- 

 tion. The fossils in question, a partial list of which is given in a 

 former paper*, are found in a bed of fine greenish sand (Glauconite- 

 Sand), of no very great thickness, irregularly covering up an exten- 

 sive and valuable seam of Brown-coal, which is worked in the neigh- 

 bourhood of Magdeburg and Westeregeln. In working the coal- 

 beds, these sands are cleared away, and thus the fossils have been 

 obtained. These sands, however, do not occur over that portion of 

 the Brown-coal bed which is now being worked, and hence the im- 

 possibility of obtaining fossils ; but it is probable that they will be 

 again met with. The Brown-coal itself rests generally on a bed of 

 blue clay, which lies immediately on Bunter-sandstein or Muschel- 

 kalk. 



These Westeregeln sands appear^ from all accounts, to be the 

 oldest fossiliferous beds in Northern Germany. How far they extend 

 has not yet been fully ascertained. The next overlying fossiliferous 

 formation of Northern Germany is the Septaria-clay of Berlin, which 

 now appears, from Prof. Bey rich's report, to have been found over a 

 considerable tract of country, comprising the whole of Brandenburg 

 and a large extent of territory to the west, inasmuch as the concre- 

 tionary nodules of Sternberg contain the same fossils as the Septaria- 

 * See Quarterly Journal Geol. Soc. vol. x. p. 292. 



L 2 



