HERTFORDSniRE NATUKAI, niSTORY SOCIETY. XXXlll 



8. " Xotcs on somo Plants not proviously rocordcd as p;rowinp; in 

 certain districts near St. Albans." By A. E. Gibbs. (^Transactions, 

 Vol. I, p. 143.) 



9. " Xote on Woodcocks carrying? their Young." By George 

 Eooper, F.Z.S. {Transactions, Vol. I, p. 144.) 



10. " Notes on the Fluke in Sheep." By Alfred T. Brett, M.D. 

 (Transactions, Vol. I, p. 139.) 



ORDDfART Meetin-g, 27th April, 1880, AT Hertford. 



This meeting was held in conjunction with the Hertford Literary 

 and Scientific Institution, and was devoted to microscopical study 

 and the exhibition and examination of objects of interest lent by 

 members of the two Societies and their friends. 



Field Meetixg, 15th May, 1880. 

 RADLETT. 



Here and there, over a considerable portion of Hertfordshire, 

 there occur blocks of stone of a peculiar kind, totally different 

 from any of the strata in their immediate neighbourhood. This 

 stone, masses of which, of veiy various shapes and sizes, are thus 

 widely scattered, has long been known as the Hertfordshire con- 

 glomerate or "plum-pudding stone." It consists of rounded flint- 

 pebbles in a siliceous matrix which is generally as hard as the 

 pebbles which it encloses, and frequently even harder. Except in 

 being consolidated, it resembles a pebble-bed which occurs in the 

 lower portion of the Woolwich and Reading Series below the 

 mottled clays to which these beds owe their former name of the 

 " plastic-clay formation." 



To the north of London this series forms the base of the " London 

 Tertiary Basin," reposing immediately on the Chalk and extending 

 across the southern part of Hertfordshire in a south-westerly and 

 north-easterly direction. Just on its edge Radlett is situated, and 

 here its pebble-bed is seen to be consolidated, or formed into a con- 

 glomerate similar to that of which pieces are found scattered far 

 and wide to the north and west. Here therefore it appears that 

 we have the Hertfordshire conglomerate in situ, and it was the 

 object of this meeting to examine it at a spot where it was known 

 to be exposed. 



The members assembled at Bricket Wood Station and strolled 

 across the fields, crossing the Colne at its confluence with tlie Ver, 

 visiting a chalk-pit, noticing a large "swallow-hole," ascending 

 the hill by the Hill Farm, and descending on the Eadlett side, the 

 highest ground atfoiding an extensive view of the surrounding 

 country. After crossing the then dry bed of a tributaiy of the 

 Colne, the source of which when flowing is the Elstree Beservoir, 



VOL. I. part VIII. D 



