250 PROCEEDIXGS OF THE GEOLOGICAL SOCIETY. [Jan. 22, 



respects it is much superior to the cement made from the Lias 

 nodules obtained at Whitby. Upwards of 1000 tons of the septaria 

 are annually sent from Speeton to Hull. 



The light-coloured, very tenacious clay in which the " cement- 

 stones" are imbedded produces a very fine quahty of Portland 

 cement ; but very httle of it is at present exported, on account of the 

 cost of carriage. 



The " Coprolite-bed " at Speeton was first discovered on the shore, 

 when the sand and shingle had been removed by a storm, and after- 

 wards traced up into the cliflP. It is now worked by adits in pre- 

 cisely the same way as the " Cement-bed ;" but, as it only averages 

 five inches in thickness, this expensive mode of working is found to 

 be scarcely remunerative, and is likely to be soon abandoned. About 

 500 tons of the " Coprolites " are annually exported fi'om Speeton 

 Cliff. They consist of very dark-coloured, almost black stone, con- 

 taining much pyrites, and mingled with worn casts of shells. Samples 

 tolerably fiee from the investing clay yield from 57 to 61 per cent, 

 of phosphates. 



Inland several of the beds of the Speeton Clay are worked for 

 brick-making. 



Por most of these particulars I am indebted to Mr. E. Hunter, the 

 present lessee of Speeton Cliff, who has kindly furnished me with a 

 number of details, with permission to make any use of them I might 

 see fit. 



There now only remains the pleasing duty of expressing my 

 obligations to the gentlemen who have assisted me in this investi- 

 gation. To Mr. Etheridge, who has devoted much time to a tho- 

 rough revision of my lists of species, I am particularly indebted, as 

 well as to Mr. Davidson, who has furnished me with some valuable 

 notes on the Brachiopoda. To Mr. Leckenby, of Scarborough, my 

 thanks are especially due, not only for the use of his magnificent 

 collection, but for the communication of many facts which the cir- 

 cumstance of his being a resident in the neighbourhood had given 

 him peculiar opportunities of accumulating. Lastly, to the Curators 

 of the various Yorkshire and other museums, and particularly to Mr. 

 Henry Woodward, of the British Museum, I desire to express my 

 acknowledgments for the facilities they have always so readily 

 granted to me for studying the collections under their care. 



2. Notice of the Hessle Deipt, as it ajppeared in Sectiois^s cibove 

 FoETT Yeaes since. By Joh^t Phillips, Esq., M.A., D.C.L., F.E.S., 

 F.G.S., Professor of Geology in the University of Oxford. 



The progress of modern research has brought before us, on a great 

 scale and under various aspects, a subject which, until the series of 

 strata began to be studied by W. Smith, had hteraUy no place in 

 British geology. By that observer, first of all men, the " superficial 

 deposits," as they were called, were separated from the " regular 

 strata," and referred to a different and more tumultuous origin. 



