Mr. J. Brown on Pleistocene Deposits near Copford. 63 



The order of the component beds of these deposits was taken from 

 a cutting made for the Eastern Counties Railway. The lowest bed 

 noticed consists of blue clay, which the author refers to a great 

 detritic accumulation called "till," and which occurs extensively 

 over the northern portion of the county of Essex. The till varies 

 considerably in character and composition ; at the N. extremity of 

 the section which the author exhibited, it was described as consist- 

 ing of a stiff* tenacious clay, but within a short space it changed 

 to a sandy gravel, containing fishes' teeth and corals in great abun- 

 dance : the rock fragments have been derived from basaltic and se- 

 condary beds ; the latter afforded the fossils contained in the follow- 

 ing list, for the identification of which the author states that he 

 has been indebted to Mr. J. de C. Sowerby. Serpula illium, L. ; 

 S. tetragona, L. ; S. articulata, G. S. ; <S. granulata, C. ; Terebratula 

 rigida, U. Ch. ; T.pisum, Ch. M. ; T. striatula, L. Ch. ; Gryphcea in- 

 curva, L. ; G. dilatata, K. C. ; Inoceramus,C; Avicula incequivalvis, L.; 

 Exogyra virgula, K. C. ; Crania striata, C. ; Pollicipes maximus, C. ; 

 Ammonites Leachii, K. C. ; A. annulatus, L. ; A. dentatus, G. ; A. 

 spinosus, K. C. ; A. serratus, O. C. ; Belemnites acutus, L. ; B.pistil- 

 liforniis, L. ; Littorina carinata, G. S.; Pentacrinites basaltiformis, L.; 

 Encrinites moniliformis, O. The remains of fishes were, Otodus appen- 

 diculatus, C. ; Galeus pristodontus, C. ; Notidanvs pristis, C. ; Odon- 

 taspis rhaphiodon, C; Hybodus, U. O., which were determined for the 

 author by Mr. S. P. Woodward. 



The Pleistocene deposit at the Copford brick-field consists, in an 

 ascending order, of a bed of black vegetable matter, or peat, from 

 six inches to one foot in thickness, resting immediately upon the 

 " till :" from this stratum the following shells were procured, which 

 were named for the author by Mr. S. P. Woodward : — Vertigo pa- 

 lustris ; V. edentula ; V. pusilla ; V. pygmea ; V. substriata ; Azeca 

 tridens ; Acme fusca ; Carychium minimum ; Zua lubrica ; Clausilia 

 Rolphii ; CI. nigricans ; CI. bidens ; Succinea Pfeifferi ; S. putris ; 

 Aplexus hypnorum ; Limnius j>alustris ; L. truncatulus ; Planorbis 

 spirorbis ; P. vortex ; Pisidium pusillum ; Helix nemoralis ; H. hor- 

 tensis ; H. arbustorum ; H. lapicida ; H. rufescens ; H. hispida ; H. 

 pulchella ; H. lamellata ; H. spinulosa ; H. fulva ; Zonites rotunda- 

 tus ; Z. ruderata ; Z. cellarius ; Z. radiatulus ; Z. nitidulus ; Z. lu- 

 ridus ; Z. crystallinus ; Pupa anglica ; P. umbilicata ; P. marginata. 



Above the peat is a bed of clay and detritus about one foot thick, 

 containing many of the land and freshwater shells cited above ; next 

 above this is a second layer of peat with shells. 



At the southern extremity of the author's section, the order of the 

 beds was as follows: — 1. Diluvial clay, 3 feet. 2. White sand with 

 shells, 3 feet. 3. White calcareous marl with shells, together with 

 the bones of the elephant, ox and deer. 4. Peat with shells ( Val- 

 val a pis cinalis), 6 inches. 5. Blue clay with freshwater shells. 



The author suggests that this deposit is the bed of an ancient 

 pond, which occupied a depression on the surface of the till. 



A paper was afterwards read " On the Tin Mines of Tenassirim 

 Province." by Prof. Royle. 



The author commences by observing that though tin is found in 



