G. A. Lebour — The Carrara Marbles. 291 



The discovery of fossils of Carboniferous age in connexion with 

 the statuary marbles and their associated beds has now placed this 

 beyond doubt, although some minor points remain to be decided. 



The following classification of the Carboniferous rocks of Central 

 Italy, therefore, may be looked upon as the true one, and in giving 

 it M. Coquand very properly remarks that it is simply an exposition, 

 with the added details which time and repeated investigations have 

 brought together, of the views which he gave to the world in 1845. 



A. Permian. — The whole of the beds known as Yerrucano. 



B. Carboniferous. 



1. Coal-measure shale: Monte Jano. 



2. Shale with Spirifer glaber : Monte Jano. 



3. Saceharoidal limestones ; statuary marbles ; bardigli ; dolomites ; cippo- 



lino (micaceous limestone) : Apuan Alps, Campigliese, Gerfalco, Cetona, 

 Elba. 



C. Silurian or Devonian. — Quartzites and slates of the Veza Valley 

 (Apuan Alps). 



The fossils of these Carboniferous divisions known in this region 

 are the following : 



Of the Coal-measures : 



Neuropteris rotundifoUa, Brong. : Jano. I P. cyathea, Brong. : Jano. 



Odontopteris Schlotheimi^ Brong. : do. P. Bucklandi, Brong. : do. 



Pecopteris arboreseensy Brong. : do. Annularia longifolia, Brong. : do. 



P. acuta, Brong. : do. | Oyclopteris orbicularis, Brong. : do. 



Of the Carboniferous Limestone series (Statuary and Bardigli 

 marbles) : 



Loxonema, sp. : Cajnpiglia. 

 Plioladomy a regularise d'Orb. : Jano. 

 Ph. plicata^ A Orh.: do. 

 Cardinia tellinaria, de Kon. : do. 

 Cardiomorpha pristina : do. 



Leptcena araehnoidea, d'Orb. : Jano. 

 Spirifer glaber. Sow. : do. 

 CyatJiocrinus quadrangularis , Miller : do. 

 Ceriopora irregularis, d'Orb. : do. 

 Astnea, sp. : Carrara. 



It may be noted that instead of Savi's supposed mass of metamor- 

 phic Cretaceous rocks, we have represented in the region of Tuscany 

 all the geological stages, from the Inferior Oolite to crystalline schists, 

 probably of pre- Silurian age, lying upon still older granite. The 

 Calcare rosso, which throughout the investigation of these rocks has 

 been of the highest importance, as giving first a pal^ontological 

 basis of operations, returns to the place which its fossils gave it 

 when first found in 1845, namely, to the Middle Lias. The various 

 vicissitudes which this horizon and that of the statuary marbles have 

 suffered during the last half century may be summed up as follows : 



The Calcare rosso ammonitifero has in turn been referred to the 

 following geological stages : 



1. Middle Lias. 1843, Coquand. 



2. Oolite (without further specialization). 1843, Savi. 



3. Terebratula diphya zone (Diphyakalk). 1845 and 1847, Pilla ; 1846, 



de Vecchi. 



4. Upper Jurassic. 1846, Savi. 



5. Partly Upper Oolite and partly Upper Lias. 1851, Savi and Meneghini; 



1856, Cocchi. 



6. Top of Infra Lias. 1862, Savi. 



7. Top of Lower Lias. 1862, Capellini ; 1864, Cocchi. 



8. Lias (without further specialization). 1865, Meneghini. 



9. Middle Lias. 1875, Coquand. Generally admitted. 



