﻿38 GEOLOGICAL MEMOIRS. 



lites, and a Pecten has also been found in them. They are of a 

 much sandier nature than the true nummulitic limestones of the 

 Karst, and are of a dark colour, probably from oxide of iron. It 

 was noticed above that on the lower surfaces of the beds of macigno, 

 protuberances occur which impress the clayey beds below them ; and 

 by attending to this indication I satisfied myself that not only the 

 beds of limestone but the whole system was doubled up on itself*. 



At one point the upper bed of limestone was broken into several 

 pieces ; yet the macigno immediately above the fragments was not 

 broken, but merely bent. Further on, the same bed is seen to be 

 broken in several parts, which, as in the former case, have been 

 thrust one against the other ; after this it bends upward and is no 

 more seen. 



Similar phsenomena may be seen on the coast at St. Andrea, by 

 following the beautiful promenade along the sea, which exhibits these 

 beds very highly inclined, though but a few toises high. Here a 

 pretty thick limestone band is seen in the macigno, the upper part 

 of it being of an arenaceous character and containing vegetable re- 

 mains (Fuci) ; whilst its lower part here also contains numberless 

 Foraminifera, principally small Nummulites, which sometimes form 

 protuberances on the under surface of the limestone similar to the 

 sandy concretions on that of the macigno. 



[The author gives a section which exhibits the macigno with the 

 included band of limestone bent into two synclinal and two anti- 

 clinal folds.] 



The surfaces of the cracks in the rock are covered with beautiful 

 rhombohedral crystals of calcspar, which is well seen at the spot last 

 indicated on the Opchina road. A remarkable circumstance which 

 is distinctly seen is this, that the upheaving force which has caused 

 the breaking of the limestone has only bent the macigno ; clearly 

 indicating, that at the time when these masses were crushed together, 

 the limestone must have already become rigid, whilst the macigno 

 must still have been soft and pasty ; while it is equally clear that 

 the macigno since that elevation has undergone no other considerable 

 movement, otherwise the crown of the arch, which is not of hard 

 materials, must have cracked, of which there is not the slightest 

 trace. 



Relying on this as proved, we may consider the presence of Num- 

 mulites on the under surface of the limestones and in the macigno 

 as their natural position, without supposing an inversion of the beds 

 or a thrusting of them one over the otherf. 



The same limestone, or a very similar one, is seen in a low hill at 

 the Bay of Servola, where it is perpendicular as well as the beds 

 which contain it. 



Similar relations, but on a far larger scale than at St. Andrea, and 

 attended with greater confusion, are seen at the south-west extremity 

 of the peninsula of Servola. Beds of sandstone, about three feet 

 thick, which compose the hill, are first seen bending downwards, and 



* [This is illustrated by a diagram. — Tbansl.] 

 f Comp. H. von Morlot's Memoir on Istria, p. 25. 



