older Deposits of the North of Germany and Belgium. 251 



ber of organic remains, was first pointed out by M. Beyrich*. The beds in 

 question protrude in the slopes of the left bank of the river near the spot called 

 Mlinchen-Miihle, about two miles above Villmar, and nearly one mile above the 

 village of Arfurth. Here the descending order of the strata is as follows : — 



Fig. 4. 



Left bank of the Lahn, near Munchen-Muhle. 







Schaalstein. ' SS,3S .^KKMW^^^ Schaalstein, with 



slaty cleavage. 



1st. Beds of weathered, white, decomposing limestone in a state resembling incoherent, gritty chalk 

 marl, or calcaire grossier. 2nd. Bluish grey limestone with white veins decomposing to a buff or fawn 

 colour. 3rd. Schaalstein, in cliffs of fifty and sixty feet in height, rising at an angle of 4-0° from beneath 

 the above. The schaalstein is in parts almost crystalline, but is both regularly bedded and jointed, and 

 also partially traversed by a cleavage oblique to the bedding. 



The shells which occur in the white or upper beds identify the deposit beyond all doubt with the 

 Devonian limestones of Westphalia. Besides the Strigocephalus Buriini, Bellerophon lineatus, Tere- 

 bratula prisca, and several Devonian corals, such as Favosites polymorpha and F. Spongites, we find 

 here six species of Turritella (Murchisonia?), two of which, T. bilineata and T.coronata, are very 

 abundant near Elberfeldt. The entire absence of the Nautilacece, so common in other parts of this region 

 where rocks of the same age abound, is remarked upon by M. Beyrich. We should however recollect, 

 that all the fossils from the spot in question have been found in beds a few feet in thickness, and that 

 they therefore characterize only one very small member of the Devonian system Associated with 

 several TerebratulcB of the Eifel, M. Beyrich found here an Ostrea, a genus which was thought to exist 

 only in strata of much less antiquity. 



On the whole, however, the fossils of Miinchen-Miihle have a true intermediate character, inclining 

 rather more to the carboniferous than to the Silurian types ; and we therefore infer that they lie in the 

 upper limestones of the Devonian system. 



Near Arfurth, where the Lahn runs in a great rent, the strata on the right bank dipping to theN.N.E. 

 and those on the left bank to the S.S.W., a limestone of grey colours alternates with schaalstein and 

 schist, and contains corals, Goniatites, and some small Trilobites. In descending the river to Villmar it 



Fig. 5. 

 River Lahn near Arfurth. 



Decomposed marly ■'>*?^^;i>5«a /\ \\\ ^X 



white limestone. , ' < ;^^V "^ \ ^ \ ^ ' Schaalstein. 



__. - t{!^^ __'j . 



Limestone. Limestone. 



* Owing to M. Beyrich's imperfect indication of this spot, we made two visits to Villmar before 

 we were able to find it out. Much of the limestone along the river banks near Arfurth disintegrates 

 into a whitish, granular, incoherent substance, like that at Mvinchen-Miihle, but the latter is the only 

 locality in which we observed many fossils. On the second occasion we were accompanied by M. E. 

 de Verneuil. 



