Reviews — Delesse's Lithologie du Fond des Mers. 75 



Settle." Alludes to papers of Messrs. Dawkins and Tiddeman, stating 

 the clay overlying the lower cave earth to be of glacial origin, which 

 the author thinks improbable, the laminated clay occurring " in the 

 cave on the surface at a point where it can only be of most recent 

 origin, near the dome which terminates in a ' pot-hole,' by which " 

 the clay has entered, derived from the glacial clays lying in hollows, 

 on the surface of the ground, as are similar clays, occurring in other 

 caverns where a theory of glacial introduction would be possible. 

 The author also differs from Mr. Tiddeman, who ascribes the base 

 of the talus at the entrance to glacial age, in believing it to have 

 been formed by matter falling from above, finding in that part of 

 the talus a smoothly rounded limestone boulder like those occurring 

 in "pot-holes," and from other reasons, the whole resting on the 

 original entrance to the cave, which afterwards became covered up. 



Spenoe, Mr., F.C.S., communicated the fact to the Society that an 

 African diamond immersed in fine clay in a small crucible, subjected 

 to a heat, at no time beyond cherry red, entirely volatized and dis- 

 appeared after three days' exposure. 



Williamson, Prof. (April 1st, p. 106), alluded to the species of 

 Aster ophyllites, considered to belong to Sphenophyllum by Eenault, 

 and remarked on the very close affinity of the two genera. 



Dawkins, W. Boyd (April 15th, p. Ill), Secretary of the Committee 

 of the British Association for carrying on the explorations of Victoria 

 Cave, replies to Mr. W. Broekbank's paper, mentioned above, 

 reiterating his belief that the cave-bed at the bottom is pre-glacial, 

 and stating that so far from 100 tons of earth having fallen on the day 

 of Mr. Broekbank's visit, probably the mass weighed less than a ton. 



Plant, John, F.G-.S. (April 21st, p. 146.) "Notes on a Fossil 

 Spider in Ironstone of the Coal-measures." Discovered by Mr. Elliott 

 Hollier, in ironstone nodules in Dudley Coal-field, described by Mr. 

 H. Woodward as Eophrynus Prestvicii in Geol. Mag. 1871. 



C. B. DeE. 



I. — A Beief Account of M. Delesse's Book, "Lithologie du 

 Fond des Meks," published under the auspices of the Minister 

 of Marine a,nd of Public Works. (Paris : E. Lacroix, 1871.) 

 By G. A. Lebouk, F.G.S. 

 DELESSE divides the matter of his important work into the 

 I five following parts: — 



I. — -Preliminaries. 

 Methods adopted in studying the deposits 

 Orography of France and of its submarine shores. 



II. — Principal agents of the submarine deposits. 

 Organic agents 



[ Atmosphere. 

 ( external • • • | Fresh and brackish waters. 



I Ti o "vcfri Til r* r\ fypTi i" ^ / 



° ) ( Subterranean waters 



\ internal • • • | Eruptions. 



( Dislocations. 



