20 PEOCEEDIXGS OI' THE GEOLOGICAL SOCIETY. [NoV. 20, 



chasm of but short width has been worn away, affording a passage 

 to the- drainage of tlie basin into the Torridge. It is plain that a 

 freshwater lake has existed here, in which clajs, brought by streams 

 from the northern slopes of Dartmoor, became deposited ; and that, 

 by the wearing down of the chasm, the lake has drained itself, and 

 the clays have become exposed in the same manner as are those of 

 Bovey basin. 



In conclusion Mr. Key observes — How strange it is that, amid the 

 proofs of teeming vegetation scattered throughout the Bovey deposit, 

 not a fragment of bone or shell should indicate the existence of 

 animal life ! Besides Coyiifene (of which the mass of the lignite is 

 supposed to be composed), numerous relics of dicotyledonous plants 

 — Cleaves and seeds — have been collected by Mr. Key, chiefly from 

 the clays at the Decoy ; and original sketches of these remains 

 accompanied the paper. Pyritous concretions, probably formed 

 around some vegetable nuclei, occur abundantly, and are also 

 illustrated in Mr. Key's MSS. After some notes on the indications 

 of an abundant flora, so well worth attentive and extended study, 

 and the apparent absence of animal remains, the author remarks, 

 that, with our present amount of knowledge, we can only suppose 

 either that no animals existed around the old lake, or, what is 

 more probable, that the conditions of the strata were inimical to the 

 preservation of animal remains. 



2. On the YoLCANic Cones o/Paterno and Motta (Sta. Anastasia), 



Etna. By Signer G. G. Gemmellaeo. 



[Communicated by Sir C. Lyell, F.E.S., F.G.S.] 



The base of that portion of the ancient basin of the Simeto which 

 extends from Catania to the Carca di Paterno is formed of pleistocene 

 clay, which is particularly exposed at the Siete della Motta and in 

 the neighbourhood of the Valley of St. Biagio. The post-pliocene 

 conglomerate, with beds of yellow sand and bands of clay, overlies 

 it, and forms the upper part of the hills of Terre-forti, extending 

 down their southern flanks as far as the broad plain of Catania, whilst 

 the freshwater calcareous tuff, which is above it, completes for the 

 neighbourhood of Paterno the series of sedimentary materials of the 

 said basin. 



This fertile district, in addition to having been exposed to the 

 pyroxenic lava-streams from Etna, has been disturbed by the de- 

 structive agency of volcanic cones. In the pleistocene period the 

 intrusion of the basalt, coeval with that of Aci-Castello, ravaged 

 the district of Yalcorrente ; and at a subsequent period two centres 

 of volcanic action existed at Paterno and at Motta (Santa Anastasia), 

 of which the traces only now remain. These, however, offer such 

 interesting phenomena, that I think it desirable to confine my remarks 

 in this notice exclusively to them. 



Volcanic Cone of Paterno. — The beautiful city of Paterno, in the 

 Province of Catania, is partly built on a mass of doleritic rock, which, 



