XCIV PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



II. Secondary. A. Cretaceous : — 



1. Cenomanian (d'Orb.). 



2. Aptian. 



3. Neocomian. 

 B. Jurassic : — 



1. Kimmeridge clay. Scolaro, and coal-beds. 



2. Coral rag ? Limestone of Mutolo. 



3. Oxfordian. Iron ores. 



III. Palaeozoic. Argillaceous schists. 



IV. Azoic. Rocks of Monte Barone. 



In the tenth volume (p. 211) of the "Nuovi Annali delle Scienze 

 Naturali" is an account, by M. Scarabelli, of the geology of 

 the province of Ravenna, accompanied by a geological map of the 

 district. The author describes it as a supplement to his former 

 work on the geology of the province of Bologna. He refers the 

 different formations to the following subdivisions — Eocene, Miocene, 

 Pliocene, Quaternary, and Modern. The oldest or eocene is com- 

 paratively unimportant. The miocene consists chiefly of a sandy 

 micaceous molasse, with few fossils, as Carcharodon crassidens^ Car. 

 angustidens, Buccinum, Tellina, and Artemis. This is overlaid by 

 a band of gypsum or selenite, which forms a lofty and conspicuous 

 crest through the country nearly parallel to the high road from 

 Bologna to Forli. The several thick beds of this deposit give al- 

 together a thickness of about one hundred metres. Its general strike 

 is N.W. to S.E. with a dip to the N.E. Resting on this gypsum 

 formation are the blue fossiliferous marls which the author refers to 

 the pliocene epoch. These marls in their upper portion become 

 gradually more arenaceous, and, by degrees, almost conglomeratic, 

 with a gentle inclination to the plain to the N.E. Marine remains 

 are very abundant, and the author considers that they show an in- 

 termixture of true miocenic and pliocenic forms. He adds a list of 

 the fossils hitherto found, from which it appears that there are 30 

 species of Bivalves and 133 of Gasteropoda. This disproportion, 

 however, can hardly be correct, particularly when we consider the 

 marly or muddy nature of the ground, so peculiarly the habitat of 

 the lamellibranchiated bivalves. It is probably owing to the greater 

 difficulty of obtaining the bivalve shells in a perfect condition. The 

 author observes that fish bones have also been fomid. The most 

 interesting feature however is, that in the upper strata, and where 

 the marls begin to pass into yellow sands, bones of Hippopotamus 

 and Rhinoceros begin to make their appearance, and these, combined 

 with littoral marine species of shells, are also accompanied by fresh- 

 water shells ; showing thereby that the bones were carried into an 

 estuary, where the marine products were mixed up with terrestrial 

 and fluviatile remains. In proof of this there has been recently 

 found in the sandy marl near the River Pratella, in a bed containing 

 Cardium edule^ Mactra triangula, Balanus, and Paludina, a collec- 

 tion of thirteen or fifteen coprolitic bodies containing traces of vege- 

 table structure, and which therefore appear to have belonged to some 



