384 Geological Society : — 



strata aro naturally separable into three divisions, viz. : — 



1. Upper Cassian Beds (or Prelongei Zone). 



2. Middle Cassian (or Muren Zone). 



3. Lower Cassian (or Stoures Zone). 



Each division is characterized by certain special lithological features 

 and palaeontological characters, everywhere recognizable. In oppo- 

 sition to the views of some other investigators, it is shown, by 

 physical and palaeontological evidence, that the Upper Cassian series 

 is normally succeeded, as originally asserted by Yon Richthofen, by 

 the well-known Schlern Dolomite, and that between this band and the 

 massive Dachstein-Kalk there is invariably found the peculiar zone 

 of the Raibl strata. 



The physical and palaeontological relationships of the disputed 

 strata of the Richthofen Riff and Sett Sass are next discussed. The 

 richly fossiliferous strata of Heiligenkreuz are shown to include 

 rocks belonging to all the three zones of St. Cassian, and a part also 

 of the Raibl. Detailed descriptions and illustrations of the dispo- 

 sition of the strata near Cortina d'Ampezzo, Seeland Thai, the Seisser 

 Alpe, &c, are given ; and in all cases it is shown that the order 

 recognized in the St. Cassian-Prelongei area is retained practically 

 unmodified, and can be satisfactorily correlated with that of the 

 Upper Trias of the Bavarian Alps. 



7. " Notes on some New and Little-known Species of Carboni- 

 ferous Murchisonia." By Miss Jane Donald. 



8. " Notes from a Geological Survey in Nicaragua." By J. 

 Crawford, Esq., State Geologist to the Nicaraguan Government. 



Nicaragua, geologically considered, can be divided, from north to 

 south, into five zones, differing from one another in lithological, 

 mineralogical, and structural characters. 



The first division embraces the central mountainous parts, and 

 contains Laurentian, Taconian, Cambrian, and Silurian rocks, also 

 Devonian rocks unconformable to the last. The second division, 

 parallel to that just named, and extending to within a hundred 

 miles of the Caribbean sea, contains sediments of Carboniferous, Per- 

 mian, and Mesozoic ages, covered unconformably by Cainozoic and 

 modern formations. In some of the rivers of this division are rich 

 gold-placers. The third division is the delta on the eastern coast. 

 Evidence furnished by alluvial deposits and coral-reefs indicates 

 recent subsidence until a few years ago, when elevation commenced. 

 The fourth division is on the western side of the first (central) 

 division. Its rocks are generally similar to those of the second 

 division. In some places dykes are connected with lava-flows. 

 In the valley of the Rio Viejo is a Tertiary mammaliferous de- 

 posit with Tillodonts, &c. The fifth division occupies Western 

 Nicaragua, and contains several small crater-lakes of the Vicksburg, 

 Yorktown, and Sumpter periods ; all the post-Mesozoic Nicaraguan 

 volcanoes are in this divison. 



Details of the economic products, the volcanic phenomena, and 

 the glaciation of the country are furnished, and the remains of Neo- 

 lithic man are recorded. 



