STACHE — GEOLOGY OP CARINTHIA AND ISTRIA. 13 



C. Inferior or Great Nummulitic Group. This is composed of 

 limestones in strong bedded masses, or in thinly foliated calcareous 

 slates, sometimes of considerable hardness. Their colour is white or 

 light-yellow, or grey passing into dark-grey and black in the thicker 

 layers. Their development throughout the whole of Istria is very 

 conspicuous ; and they may be subdivided, according to the nature of 

 their organic remains in general (Corals, Terebratulce, Alveolince, 

 Echinodermata), and the species of Nummulites included in them, into 

 several subgroups, each of them constantly keeping a fixed horizon. 



D. Lowermost or Freshwater Group. Its strata are interposed 

 between the group C and the uppermost Kudista-liinestones. Their 

 lowermost horizon is marked by grey or brown bituminous lime- 

 stones, with lenticular coal-beds, large freshwater shells, and fruits 

 of C'hara, most constantly overlain by hard smoke-grey limestones, 

 containing small freshwater Gasteropods, and, in some localities, an 

 enormous quantity of Chara. Dr. Stache gives to these strata the 

 name of " Cosina-Vrem Strata," from the places where they occur 

 most conspicuously, and he thinks them to be old Tertiaries, cor- 

 responding with certain portions of D'Orbigny's " Suessonien in- 

 ferieur" (Calcaire lacustre de Hilly). 



IV . Cretaceous Rocks. — These are very prevalent within the terri- 

 tory in question, and may be subdivided, although with some diffi- 

 culty, into three more or less distinct groups : — 



A. Superior Rudista-group, comprising limestones, of compact or 

 slaty texture, and calcareous breccia, generally of white or clear 

 colours, and including Hippurites and Radiolites, throughout their 

 range in Istria, as a nearly constant narrow zone on the margin of the 

 Nummuhtic deposits. Near Kaal they are almost entirely composed 

 of fragments of Cidarites and other Echinoderms. 



B. Middle or Radiolite-group, comprising generally dark-coloured 

 limestones, dolomitic limestones, and dolomitic breccia, with some- 

 times a strong bituminous smell. They admit again of subdivision 

 into — -1. An upper series, in which prevail limestones, alternating 

 with dolomitic arenaceous strata, and including in enormous quan- 

 tities a long and slender species of Radiolites. 2. A lower series of 

 breccia and sandstones, of essentially dolomitic character, rarely in- 

 cluding organic remains, or subordinate limestone-beds. These two 

 series together constitute the plateau of the Schneeberger-Vfald, 

 the Schneeberg itself (5673 ft.), the N.E. portion of Istria, and all 

 the Karst region. 



C. The Inferior Rudista-group ; with two subdivisions : — 



1. Upper series composed of limestones in laminae, with corneous 

 silex, and marly, dark-coloured, bituminous, calcareous slates, known 

 long ago to yield a few remains of Fishes near Comen and in some 

 other localities. 



2. A lower scries of undoubtedly Ncocomian origin, which may 

 be also called Caprotina-limcstones, on account of a species of these 

 bivalves (probably Capr. ammonia) occurring very frequently in 

 the yellow or grey limestones composing it. This group may be 

 distinctly traced along the railroad from Laasc to Loitsch. 



