1856.] BUNBURY DRAINED MERE. 355 



several writers * who have treated of the lignites and the geology of 

 the neighbourhood. Lastly, Dr. Croker supplied some notes on the 

 local occurrence of the numerous varieties of rocks and minerals in 

 the vicinity of the Teign, such as ores of lead, manganese, and iron, 

 also labradorite, schorle, &c., all of which, as well as the lignite and 

 its vegetable remains, were illustrated by a large series of specimens. 



3. Notice of some appearances observed on draining a Mere 

 near Wretham Hall, Norfolk. By Charles J. F. Bun- 

 bury, Esq., F.R.S., F.G.S. 



Wretham Hall, the seat of Wyrley Birch, Esq., is situated about 

 six miles north of Thetford, in that extensive tract of open sandy 

 plains which occupies much of the south-western part of Norfolk 

 and of the north-western part of Suffolk ; a tract which may be 

 called upland in comparison with the fens, but of very moderate ele- 

 vation above the sea-level, as is shown by the slow course of the 

 streams flowing from it. About "Wretham there are several meres, 

 or small natural sheets of water, without any outlet. The one to 

 which my attention was particularly called by Mr. Birch occupied 

 about forty-eight acres, and was situated in a slight natural depres- 

 sion, the ground sloping gently to it from all sides. The water has 

 been drawn off by machinery, for the purpose of making use, as 

 manure, of the black peaty mud which formed the bottom. This 

 black mud, which is in parts above 20 feet deep, is nothing else 

 than a soft, rotten, unconsolidated peat ; or perhaps it should be 

 described as vegetable matter in a more complete state of decom- 

 position than ordinary peat, showing no distinct trace of vegetable 

 structure. At the depth of about 15 feet, in this peat, occurs a 

 distinct horizontal layer, from 2 to 6 inches thick in various parts, 

 of compressed but undecayed moss, unmixed with any other sub- 

 stance. The stems and leaves of the moss, though closely matted 

 together, are easily separable, and are in so good a state of preser- 

 vation as to show their distinctive characters very clearly under the 

 microscope. All that I have examined belong to one species, — 

 Hypnum jiuitans ; a moss by no means uncommon in watery bogs 

 and fenny pools throughout the British Islands, and often growing 

 in dense masses in shallow water. The layer that I speak of is of 

 considerable extent, although apparently not extending over the 

 whole area of the mere, as there are parts in which the whole thick- 

 ness of the black mud has been penetrated without finding it. 

 While wet and fresh, it is of a bright rusty red colour, turning to a 

 yellow brown when dry. What is remarkable, I think, in this case, 

 is the occurrence of a distinct bed of moss, perfect and undecayed, 

 beneath 15 feet of mud, in which no trace of moss is to be seen. 



* See Phil. Trans, vol. li. p. 534 ; Parkinson's * Organic Remains,' vol. i. pp. 112, 

 126 ; Trans. Geol. Sec. 2 ser. vol. vi. p. 439 ; and De la Beche's ' Report on the 

 Geology of Devon,' &c., p. 143. 



